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.
Parts of Lviv are without power following missile strikes on Tuesday, Mayor Andriy Sadovyi said.
Two power substations were damaged as a result of the strikes on the western Ukrainian city, near the Polish border.
It's not clear if there are any casualties.
Ukraine's lead prosecutor, Iryna Venediktova, said Russian President Vladimir Putin should "absolutely" be prosecuted for the war crimes she says occurred in the town of Irpin and surrounding communities.
"He’s the main war criminal of the 21st century," she said.
"We all know who started this war. And this person is Vladimir Putin," she said.
Venediktova said the first phase of the war crimes investigation in Irpin has ended. She said investigators found evidence of rape, torture and the use of banned weapons of war in the city.
-ABC News' Marcus Moore
Russia's military is "now significantly weaker, both materially and conceptually," than it had been prior to its invasion of Ukraine, the U.K. Ministry of Defense said on Tuesday.
"Recovery from this will be exacerbated by sanctions," the ministry said in an intelligence update. "This will have a lasting impact on Russia's ability to deploy conventional military force."
President Joe Biden will head to Troy, Alabama, on Tuesday to visit a Lockheed Martin facility that manufactures weapons systems such as Javelin anti-tank missiles, which have been key in Ukraine’s defense against Russia.
Javelin missiles "are lightweight, portable, shoulder fired, anti-tank weapons system that can hit targets up to 2.5 miles away," White House press secretary Jen Psaki said Monday. "They're highly lethal, and we've sent over 5,500 Javelin anti-armor systems to Ukraine to support the Ukrainian people's fight for freedom.”
This facility can manufacture up to 2,100 Javelins per year, Psaki said.
She said Biden will also "deliver remarks about the security assistance we are providing, highlighting the urgency of the request to Congress to pass funding quickly to help Ukraine continue to succeed against Russian aggression and to make sure that the United States and our allies can replenish our own stocks of weapons to replace what we have sent to Ukraine."
Asked if there is any concern about depleting stockpiles if the U.S. keeps up this pace of giving Javelin missiles to Ukraine, Psaki said the Department of Defense ensures that the U.S. maintains enough to defend itself.
-ABC News' Justin Ryan Gomez
