(NEW YORK) — Russian President Vladimir Putin’s “special military operation” into neighboring Ukraine began on Feb. 24, with Russian forces invading from Belarus, to the north, and Russia, to the east. Ukrainian troops have offered “stiff resistance,” according to U.S. officials.

The Russian military has since launched a full-scale ground offensive in eastern Ukraine’s disputed Donbas region, capturing the strategic port city of Mariupol and securing a coastal corridor to the Moscow-annexed Crimean Peninsula.

Here’s how the news is developing. All times Eastern:

Jun 21, 7:42 am
American killed in Ukraine, officials say

U.S. citizen Stephen Zabielski has died in Ukraine, the State Department confirmed to ABC News Tuesday morning.

“We can confirm the death of U.S. citizen Stephen Zabielski in Ukraine,” a State Department spokesperson said. “We have been in touch with the family and have provided all possible consular assistance. Out of respect to the family during this difficult time, we have nothing further.”

Zabielski’s death was first reported by Rolling Stone.

US officials again cautioned Americans against traveling to Ukraine, saying “that U.S. citizens in Ukraine should depart immediately if it is safe to do so using any commercial or other privately available ground transportation options.”

-ABC News’ Matthew Seyler

Jun 21, 5:39 am
Russia intensifies threats, announces retaliatory strikes

Following Ukraine’s attack on three oil drilling platforms in the Black Sea off the coast of Russian-annexed Crimea on Monday, Russian officials announced plans to strike critical Ukrainian targets in retaliation.

“The attack on the Chernomorneftegaz towers unleashes Russia’s hands,” Mikhail Sheremet, a Russian member of parliament, said on Monday as quoted by Russian media. “Retaliatory strikes on decision-making centers will be carried out in the near future,” Sheremet added.

Seven people remain missing after Ukraine’s strike on the drilling platforms, a source in the emergency services of Crimea said on Tuesday.

The fire on one of the oil rigs is still continuing, Russian Federation Council member from Crimea Olga Kovitidi told Interfax.

“With regards to the blaze, it is not abating on the oil rig. The fire approached the well overnight,” Kovitidi said.

On a day filled with intimidation tactics, Russia extended its threats to Lithuania on Monday, calling the Baltic country’s decision to suspend the transit of EU-sanctioned goods to the Russian Kaliningrad region “unprecedented” and “illegal.”

On June 18, Lithuania notified the Kaliningrad Railway of suspending the transit of EU-sanctioned goods through its territory. Up to half of ready-to-import goods, including building materials and metals, are subject to the ban, Kaliningrad region Governor Anton Alikhanov said.

The Russian Foreign Ministry summoned the Lithuanian Chargé d’Affaires on Monday and warned the Baltic diplomat of repercussions if freight transit to the Kaliningrad region is not restored in full in the near future.

“Russia reserves the right to take action to protect its national interests,” the Russian ministry told the Lithuanian official as reported by local media.

Ukrainian Foreign Minister Dmytro Kuleba said in a tweet on Monday that “Russia has no right to threaten Lithuania.” According to Kuleba, “Moscow has only itself to blame for the consequences of its unprovoked and unjustified invasion of Ukraine.”

Yet on the same day, Russian officials announced military drills of the Baltic Fleet in the Kaliningrad region.

Several hundred firings of multiple rocket launcher systems, large-caliber guns and other artillery will be carried out during the exercises, the Baltic Fleet stated on Monday.

Maneuvers in the Kaliningrad region on Monday involved about 1,000 servicemen and more than 100 combat units, including special artillery equipment and missile units, according to Russian media.

Andriy Yermak, who heads the Ukrainian Presidential office, said Russia’s attempts to threaten Lithuania “are a challenge for the European Union and NATO.”

“Now it is important to maintain a stable position and not make concessions to Russia on sanctions and restrictions on the transit of goods from Russia to Kaliningrad,” Yermak said on Monday.

Any concession will be perceived by Russia as a weakness, the Ukrainian official added.

-ABC News’ Edward Szekeres, Max Uzol, Tatiana Rymarenko and Yuriy Zaliznyak

Jun 20, 4:17 pm
Kremlin spokesperson addresses missing Americans, Brittney Griner

Kremlin spokesperson Dmitry Peskov told MSNBC that Americans Andy Tai Ngoc Huynh and Alexander Drueke, who were captured while fighting in Ukraine, “committed crimes,” and that they were not part of the Ukrainian armed forces and therefore not subject to the Geneva Conventions.

“They were involved in firing and shelling our military personnel, they were endangering their life and they should be responsible. They should be held responsible … for those crimes that they have committed,” he said.

The Geneva Conventions outline the humanitarian rights given to prisoners of war, however, mercenaries are not given the same protections.

Regarding WNBA star Brittney Griner, who has been detained in Russia since February, Peskov said she’s not a hostage.

He said Russia has strict drug laws and she was caught carrying banned substances.

Griner was taken into custody at an airport near Moscow after officials allegedly found vape cartridges with hashish oil in her bag. Hasish oil is illegal to possess in Russia. The U.S. government has classified her case as “wrongfully detained,” which means that the U.S. would work to negotiate her release.

Jun 20, 4:09 pm
Ben Stiller, a goodwill ambassador with UNHCR, visits Ukraine

Actor Ben Stiller, a goodwill ambassador for the United Nations High Commissioner for Refugees for the last five years, is visiting Ukraine to highlight the refugee crisis.

“I’m here meeting people forced to flee their homes due to the war in Ukraine. People have shared stories about how the war has changed their lives — how they’ve lost everything and are deeply worried about their future,” Stiller said Monday from Ukraine.

“Protecting people forced to flee is a collective global responsibility,” he said. “We have to remember this could happen to anyone, anywhere.”

Stiller was seen meeting with Ukrainian President Volodymyr Zelenskyy on Monday. Stiller told the actor-turned-president, “What you’ve done and the way that you’ve rallied the country and for the world, it’s really inspiring.”

Stiller also met with displaced people in Poland.

-ABC News’ Christine Theodorou

Jun 20, 2:10 pm
Russians launching large-scale offensive in Luhansk region

Serhiy Haidai, the head of the Regional Military Administration in Luhansk in eastern Ukraine, said the situation along the entire Luhansk front is “extremely” difficult with Russian forces “launching a large-scale offensive in our region.”

“They have accumulated a sufficient number of reserves and today all the free settlements of the region are on fire,” Haidai said.

The city of Lysychansk in the Luhansk Oblast has been coming under “massive” Russian fire all day, he said, with the number of victims unknown. He said Russian forces are advancing along the Lysychansk-Bakhmut highway and nearby settlements are under constant fire.

Haidai added that Ukrainian troops are only in control of the Azot chemical plant in Severodonetsk.

Copyright © 2022, ABC Audio. All rights reserved.

(KYIV, Ukraine) — It was a dark night when Oleksandr, a 51-year-old pilot, was set to fly to Mariupol.

“I have more than 30 years of experience. But this was the most difficult flight in my career,” he said of the mission he flew on April 4, more than a month into the Russian siege of Mariupol.

The Azovstal steel plant was at the time the city’s last stronghold for the Ukrainian troops, including many who were severely wounded, as well as hundreds of civilians who were sheltering there. While the Ukrainian authorities tried to negotiate with the Russian side to evacuate the plant, Ukraine’s military intelligence secretly organized aid deliveries.

The mission was offered to several pilots.

“We could refuse, but my crew didn’t,” said Oleksandr, who spoke to ABC News wearing a mask. “We knew there are our people in Mariupol and we have to help them.”

The task was to deliver around 2 tons of aid from Dnipro, about 150 miles north of Mariupol, and evacuate the wounded from the plant.

Having the latest intelligence, the crew designed a route to the besieged city to bypass the Russian air-defense system. It was a just another landing-and-cargo operation, Volodymyr, a 27-year-old navigator joked, although they knew that a previous mission had failed and their colleagues had died. (The navigator also spoke to ABC News while wearing a mask. Volodymyr is a family name, used here to obscure his identity.)

Two helicopters flew at around 130 miles per hour at a super-low altitude of three to five meters to stay invisible to the enemy, the pilot and navigator said.

“We had to fly over the power lines sometimes, and that was a risky maneuver given the speed,” the pilot said.

The road to the plant was rather calm, he said. Then the helicopter landed at the plant.

“We stayed in our places, while the cargo was taken and the wounded were loaded. It lasted only 20 minutes but felt like two hours. It was so scary,” Oleksandr said.

They heard and saw explosions all around them, they said. The helicopter was shaking.

“When we took off I noticed a Russian ship in the sea and understood that they could now hit us. But my hands did the job before my brain realized how dangerous it was,” the pilot said.

The helicopter continued the daring ride and safely landed in Dnipro at dawn.

“I turned around to the guys we evacuated. And I saw so much gratitude in their eyes,” he said. “We had only 15 minutes to talk, I found out that some of them were married, one soldier’s wife was pregnant and he said he was so much looking forward to seeing her… Unforgettable moment.”

According to the head of Ukraine’s military intelligence, Kyrylo Budanov, there were seven such missions to Azovstal during the Russian siege. Some pilots never returned, President Volodymyr Zelenskyy later told the media. One of Oleksandr’s friends was among those who went missing.

“We were on our way back from Mariupol,” he said. “And I heard the pilot of the second crew saying they are seven kilometers from the contact line and have only 250 liters of fuel left. That’s three times less than we had, so I presumed that their helicopter was damaged. That was the last phrase I heard from my friend.”

They later found the crashed helicopter, but there were no bodies in or around it, he said.

“That’s why we still hope they are alive,” Oleksandr said.

The remaining Ukrainian soldiers in the Azovstal surrendered in mid-May. Ukrainian officials said the order was given to save the lives of the troops, who are now supposed to be exchanged.

Both the pilot and navigator who spoke to ABC News declined to make any judgements about the surrender. It probably had to be done, they said. But if they were again asked to carry that risky mission, they would probably do it, Volodymyr, the navigator, said.

“That flight changed me, I now appreciate life more,” he said. “But If I were told that I’m the only one who can do that I would accept the challenge.”

Copyright © 2022, ABC Audio. All rights reserved.