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.
Apr 05, 2022, 1:11 PM EDT
11 million people have been evacuated from Ukraine
An estimated 11 million people have been evacuated from Ukraine since Russia invaded the country on Feb. 24, the U.N. International Organization on Migration said Tuesday.
Families arrive at the main train station as they flee the eastern city of Kramatorsk, in the Donbas region of Ukraine, on April 3, 2022. "The rumor is that something terrible is coming," said Svetlana, a volunteer organizing the crowd on the station platform.
Fadel Senna/AFP via Getty Images
The organization also reported that more than 7.1 million people have been displaced within Ukraine as of April 1. That figure comes on top of the one from the U.N. High Commissioner for Refugees showing more than 4 million people have fled abroad.
The International Organization on Migration said more than 2.9 million people still in Ukraine are actively considering "leaving their place of habitual residence due to war."
Apr 05, 2022, 12:38 PM EDT
Satellite images of bodies in Bucha contradict Russia's claims
An ABC News analysis of videos and satellite imagery confirms that some of the bodies seen lying in the streets of Bucha were there as early as March 19, when the Ukrainian city was still occupied by Russian forces, contradicting Russia's claims that the scene was "staged" after its troops left.
A view of Yablonska Street in Bucha, Ukraine, March 19, 2022, in a satellite image. Satellite photographs released on April 4, 2022 appear to rebut Russian assertions that dead bodies in civilian clothing found in Bucha had appeared there after Russian forces retreated from the devastated Ukrainian town.
Maxar Technologies via AFP/Getty Images
As Ukrainian authorities regained control over Bucha, northwest of Kyiv, gruesome images emerged earlier this week showing numerous bodies of dead civilians -- some shot at close range and with their hands bound -- strewn across streets and in mass graves. Russia has denied responsibility, calling the footage "fake" and saying that all of its units withdrew completely from Bucha around March 30.
In this photo taken in Irpin, Ukraine, on April 1, 2022, a vehicle belonging to the International Committee of the Red Cross (ICRC) is seen on a damaged street as the organization delivers food and first aid to residents.
ICRC via Reuters
However, satellite images provided by Maxar Technologies show that at least five of those bodies had been on the street in Bucha since March 19, when Russia said it still occupied the town. ABC News' Visual Verification team compared the satellite imagery to videos of the same scene posted on Twitter by Ukrainian authorities on April 2, as well as footage taken by ABC News journalists in Bucha on April 4.
The satellite imagery of Bucha in March was first reported by The New York Times.
-ABC News' Alice Chambers
Apr 05, 2022, 11:59 AM EDT
Zelenskyy details atrocities to UN Security Council
In an address to the United Nations Security Council on Tuesday, Ukrainian President Volodymyr Zelenskyy laid out the atrocities he said were committed by Russian forces in Bucha, including women shot in front of their homes and raped in front of their children.
"There is not a single crime they would not commit," Zelenskyy told the council via a live video feed from Kyiv.
Zelenskyy proposed a summit to reform the world’s global security apparatus, listing a number of major conflicts since World War II he said the U.N. Security Council had failed to prevent.
He said Russia's actions in Bucha, a town northwest of the Ukrainian capital, are no different from other acts of terrorism.
"Here it is done by a member of the United Nations Security Council destroying internal unity borders, countries," Zelenskyy said.
He accused Russia of "pursuing a policy to kill ethnic and linguistic diversity."
Ukrainian President Volodymyr Zelenskiy appears on a screen as he addresses the United Nations Security Council via video link during a meeting at the United Nations Headquarters in New York City, April 5, 2022.
Andrew Kelly/Reuters
Zelenskyy went on to criticize the council for failing to provide security to Ukraine, saying, the U.N. "simply cannot work effectively."
"If this continues, countries will have to rely on their selves, not (the) international community," Zelenskyy said. "The U.N. will be ready to close. Do they think the time of the U.N. is gone? If no, then the U.N. must act immediately."
Zelenskyy added, "accountability must be inevitable."
Telling the council he was speaking on behalf of the deceased, Zelenskyy detailed in graphic detail the horrors found in Bucha, describing them as "the most terrible crimes we have seen since the end of World War II.“
"The Russian military searched for and purposefully killed anyone who served our country. They killed –-- shot and killed women outside their houses when they just tried to call someone who is alive. They killed entire families, adults and children, and they tried to burn the bodies," Zelenskyy said. "I am addressing you on behalf of the people who honor the memory of the deceased, every single day in the memory of the civilians who died, who were shot and killed in the back of their head after being tortured, some of them were shot on the streets. Others were thrown into the wells, so they died. They are in suffering."
Noting Russia's veto power on the council, Zelensky proposed the council remove Russia's power so it "cannot block decisions against its own aggression" or else "dissolve yourselves altogether."
Zelenskyy's address was met with applause by the members of the council.
15:03
Zelenskyy addresses UN Security Council
Ukrainian President Volodymyr Zelenskyy spoke to members of the UN Security Council amid international outrage of alleged atrocities in Bucha, Ukraine.
Apr 05, 2022, 11:43 AM EDT
Video shows Russian shell hitting ambulance outside children's hospital
Video has emerged purportedly showing a Russian shell striking an ambulance parked outside a children's hospital in the Ukrainian city of Mykolaiv.
Security camera footage released by Mykolaiv Gov. Vitaly Kim shows the moment the empty ambulance is hit and explodes next to the hospital on Monday.
As of March 30, there had been 82 attacks on health care in Ukraine since Russian forces invaded, resulting in at least 72 deaths and 43 injuries, including patients and health workers, according to the World Health Organization.
