The Americans, Andy Tai Ngoc Huynh and Alexander Drueke, are both from Alabama.
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.
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A look at the two leaders at the center of the war in Ukraine and how they both rose to power, the difference in their leadership and what led to this moment in history.
Valeriy Zaluzhniy, the commander in chief of Ukraine's Armed Forces, said Ukrainian troops targeted two Russian naval vessels in the Black Sea on Monday.
He shared video on his Facebook page that he says shows drones striking the boats.
Russian officials have not confirmed the strikes.
-ABC News' Irene Hnatiuk
The Lysychansk Gymnasium, an acclaimed secondary school in Ukraine's Luhansk region, burned to the ground after coming under fire in targeted shelling, said Serhiy Haidai, the head of Luhansk's Regional Military Administration. The school was more than a century old.
-ABC News' Max Uzol and Irene Hnatiuk
Ukrainian forces have carried out an offensive in the country's Kharkiv region, taking back control of several settlements, Ukraine's Ministry of Defense said Monday. This includes the settlements of Verkhnya Rohanka, Ruska Lozova, Slobidske and Prilesne.
-ABC News' Irene Hnatiuk
U.S. Embassy staff returned to Ukraine for the day on Monday, marking the first trip back in the country since February.
"We expect to continue to do day trips for the next week or two and we very much hope that the conditions will permit us to go back to Kyiv by the end of the month," Kristina Kvien, the U.S. chargé d'affaires to Ukraine, said in a statement.
Kvien said, "The message to Russia is: you failed -- Ukraine is still standing, the government is still functioning and we are going back to Lviv first and then Kyiv to help the government."
Kvien continued, "We are listening to the security professionals and when they tell us we can go back we go back. And while we are eager to do so we also want to make sure we are listening to the experts. So, the fact that we are here in Ukraine means that the security officials just said that it is ok and safe to meet here in Lviv and hopefully we will get the clearance to go back to Kyiv."
-ABC News' Clark Bentson
