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.
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.
Apr 12, 2022, 1:45 PM EDT
403 bodies recovered in Bucha: Mayor
In a televised announcement on Tuesday, Anatoliy Fedoruk, the mayor of Bucha, Ukraine, said that the bodies of 403 people presumably killed by Russian forces have been recovered in his city and that he expects the number to rise.
Fedoruk said 16 residents of Bucha remain unaccounted for and are presumed dead.
Police officers work on identifying bodies of civilians, before sending them to the morgue, in Bucha, northwest of Kyiv, Ukraine, on April 6, 2022.
Rodrigo Abd/AP
He said 163 of the 403 bodies recovered have been identified.
Fedoruk alleged last week that nearly all of those killed in Bucha are civilians.
Surviving residents of the besieged town told an ABC News crew in Bucha last week that Russian troops allegedly tortured people before killing them and executed many men under the age of 50.
When ABC News arrived in Bucha on Tuesday, bodies still lay in the streets.
Russia has denied committing atrocities in Ukraine and said it is not targeting civilians.
-ABC News' Christine Theodorou
Apr 12, 2022, 1:10 PM EDT
US concerned Russia could disguise chemical weapons: Official
A senior U.S. defense official said Tuesday that the United States cannot confirm whether Russia used chemical agents in Mariupol or elsewhere in Ukraine but that the Pentagon is concerned Russian forces could disguise such attacks.
The Department of Defense has seen evidence Russia has considered disguising the use of chemical weapons by making them appear to be more benign riot control agents, the official said.
Emergency workers remove debris of a building destroyed in the southern port city of Mariupol, Ukraine, April 10, 2022.
Alexander Ermochenko/Reuters
"In the past we've had indications that that could be one thing that the Russians look at is the potential mixing of agents with the idea that they could disguise a more serious attack by using the vehicle and the techniques of riot control agents," the official said.
Pentagon press secretary John Kirby released a similar statement Monday night to address social media reports claiming Russia used a chemical weapon in Mariupol.
"These reports, if true, are deeply concerning and reflective of concerns that we have had about Russia’s potential to use a variety of riot control agents, including tear gas mixed with chemical agents, in Ukraine," Kirby said.
-ABC News' Matt Seyler
Apr 12, 2022, 12:42 PM EDT
Blinken meets with UN refugee chief amid Ukraine crisis
U.S. Secretary of State Antony Blinken was meeting Tuesday morning with U.N. refugee agency chief Filippo Grandi amid the crisis in Ukraine and other upheavals that have displaced people around the globe.
"We've only seen that challenge increase and, of course, Ukraine is now added to the mix with Russian aggression displacing, within Ukraine or outside of Ukraine, two-thirds of the children in that country, as well as, of course, many, many adults," Blinken said while sitting across the table from Grandi.
A woman cries as she holds her baby after they have arrived with other evacuees from Mariupol, as Russia's invasion of Ukraine continues, in Zaporizhzhia, Ukraine, March 29, 2022.
Marko Djurica/Reuters
There are some 95 million people displaced across the globe, with the number of refugees alone larger than the populations of Spain or South Korea, Blinken said.
Blinken added the United States is "grateful" for the work the U.N. High Commissioner for Refugees is doing to meet the needs of refugees. He said the United States is working with the agency to both resettle refugees in the United States and care for refugee populations overseas.
Grandi praised the United States for being the largest donor and the largest resettlement country for refugees.
But weeks after the Biden administration said it would admit up to 100,000 Ukrainian refugees, Grandi said the White House has released no details about how the United States will do that.
"This figure that he (Blinken) mentioned -- 95 million -- maybe 96 million by today, who knows?" Grandi said, adding that the number of refugees had gone up by 12 million in less than two months with the crisis in Ukraine.
Grandi noted other crises from Afghanistan to Africa and Venezuela that have displaced people and said of Russia's war in Ukraine, "That crisis should not make us forget everything else."
-ABC News Conor Finnegan
Apr 12, 2022, 8:59 AM EDT
Putin calls Russia's objectives in Ukraine 'noble'
Russian President Vladimir Putin said Tuesday that his country's "special military operation" in Ukraine would undoubtedly achieve its "noble" objectives."
"On the one hand, we are helping and saving people, and on the other, we are simply taking measures to ensure the security of Russia itself," Putin said, according to Russian news agencies. "It's clear that we didn't have a choice. It was the right decision."
Russian President Vladimir Putin, Belarusian President Alexander Lukashenko and Director General of Roscosmos Dmitry Rogozin visit the construction site of the Amur launch complex for Angara rockets at the Vostochny Cosmodrome in Amur Region, Russia April 12, 2022.
Kremlin via Reuters
Putin made the comments while visiting the Vostochny Cosmodrome, a Russian spaceport in the Amur Oblast in the Russian Far East, to mark Russia's annual Cosmonautics Day.
He was joined by Belarusian President Alexander Lukashenko. The two leaders held talks on bilateral relations and the situation in Ukraine, without the participation of Russian or Ukrainian delegations.
