Russian President Vladimir Putin's "special military operation” into Ukraine began on Feb. 24, with troops crossing the border from Belarus and Russia. Moscow's forces have since been met with “stiff resistance” from Ukrainians, according to U.S. officials.
Russian forces retreated last week from the Kyiv suburbs, leaving behind a trail of destruction. After graphic images emerged of civilians lying dead in the streets of Bucha, U.S. and European officials accused Russian troops of committing war crimes.
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.
Here's how the news is developing. All times Eastern.
Mar 16, 2022, 3:17 PM EDT
Biden calls Putin a 'war criminal' for 1st time
"I think he is a war criminal," President Joe Biden said Wednesday of Russian President Vladimir Putin.
Russian President Vladimir Putin attends a meeting with Belarusian President Alexander Lukashenko at the Kremlin in Moscow, March 11, 2022.
Sputnik/via Reuters
The president initially told the reporter "no" when asked if he was ready to label Putin a war criminal, but moments later Biden circled back, asking her to repeat the question.
This marked the first time Biden has called Putin a war criminal since the invasion began. The White House had previously said there was an official review underway before the administration could formally accuse Putin of war crimes.
-ABC News' Mary Bruce
Mar 16, 2022, 2:56 PM EDT
Kidnapped Melitopol mayor freed from Russian captivity
Ivan Fedorov, the mayor of the occupied Ukrainian city of Melitopol, has been freed after being kidnapped by Russian troops, according to Ukrainian officials.
Fedorov was freed in a "special operation," Kirill Timoshenko, the deputy head of Ukraine's presidential office, said. He didn't give additional information.
His kidnapping was reported on March 11.
Ukrainian President Volodymyr Zelenskyy released a video of him talking to Fedorov on the phone. The president told the mayor he was very glad to speak with him and said, "We don't leave ours behind."
-ABC News' Patrick Reevell
Mar 16, 2022, 2:26 PM EDT
UNICEF highlights dangers Ukrainian children face as refugees
More than half of the 3 million people who have fled Ukraine are children, according to UNICEF.
“We realized that it’s about 75,000 a day… that’s about 55 Ukrainian children becoming refugees every minute. Essentially, one every second since this war started,” UNICEF spokesperson James Elder told ABC News Live.
Raquela, 2, and Manuela watch cartoons on an iPhone at Dumbraveni sports arena which has been converted to a temporary shelter, after they fled with their families from the beseiged Ukraine in Suceava, Romania March 15, 2022.
Clodagh Kilcoyne/Reuters
Aleina, left, looks on as nurses tend to her baby Snizhana seconds after giving birth in the maternity ward while sirens announce air raids in Mykolaiv on March 14, 2022. Almost half of the 49 women have had to give birth in the basement since Feb. 24. Mykolaiv is the scene of violent clashes with Russian troop.
Bulent Kilic/AFP via Getty Images
Many children are suffering from a lack of food and freezing temperatures, he said.
"Many of them haven’t had clean water in two days,” he said.
Elder also highlighted the psychological trauma.
“They’ve been under bombardment. Many of them have seen family members or community members killed," he said.
Elder added that UNICEF is “desperately concerned” about human trafficking, warning that any large number of children coming into a new country are at a higher risk of being abducted.
-ABC News'Shannon Caturano
Mar 16, 2022, 1:47 PM EDT
Biden announces additional military help for Ukraine
President Joe Biden announced more aid to Ukraine Wednesday, saying that the "American people are answering [Ukrainian] President [Volodymyr] Zelenskyy's call for more help, more weapons for Ukraine to defend itself, more tools to fight Russian aggression."
Tracers are seen in the night sky as Ukrainian servicemen fire on a drone as Russia's attack on Ukraine continues, in Kyiv, Ukraine, March 14, 2022.
Gleb Garanich/Reuters
A Ukrainian serviceman stands guard at a military check point in the center of Kyiv, March 15, 2022, on the 20th day of the Russian invasion of Ukraine.
Fadel Senna/AFP via Getty Images
Biden announced an additional $800 million in military assistance as part of the $13.6 billion aid package for Ukraine contained in the government spending bill Biden signed into law Tuesday, which includes weapons the Ukrainians have been requesting, such as anti-armor and anti-air systems.
“At the request of President Zelenskyy, we have identified and are helping Ukraine acquire additional longer range anti-aircraft systems and ammunitions for those systems," Biden said. "Our new assistance package also includes 9,000 anti-armor systems -- these are portable, high-accuracy systems, shoulder-mounted missiles, that the Ukrainian forces have been using."
A firefighter works at a site of a fire, as Russia's invasion of Ukraine continues, in Kharkiv, Ukraine, March 16, 2022.
Oleksandr Lapshyn/Reuters
The U.S. is also sending drones, "which demonstrates our commitment to sending our most cutting-edge systems to Ukraine for its defense," Biden said.
The new package will also supply Ukraine with machine guns, shotguns and grenade launchers.
"This could be a long and difficult battle," Biden said. "But the American people will be steadfast in our support of the people of Ukraine in the face of [Russian President [Vladimir] Putin’s immoral, unethical attacks on civilian populations. We are united in our abhorrence of Putin’s depraved onslaught, and we are going to continue to have their backs as they fight for freedom, their democracy, their very survival."
Biden did not directly address Zelenskyy's emotional appeal to lawmakers on Wednesday for the U.S. to back a no-fly zone, which the administration has repeatedly rejected.
