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 21, 2022, 9:53 AM EDT
Ammonia leak at chemical plant in besieged city of Sumy
An ammonia leak has been reported at a chemical plant in the northeastern city of Sumy, the regional governor Dmytro Zhyvytskyy said Monday.
On his official Telegram channel, Zhyvytskyy said the leak was caused by Russian shelling.
He warned those within a 3-mile radius of the Sumykhimprom plant should leave the area because the gas is hazardous but that workers have contained the leak.
Zhyvytskyy said, so far, just one injury has been reported among employees of the plant.
-ABC News’ Joseph Simonetti
Mar 21, 2022, 9:05 AM EDT
Refugee numbers reach 3.4 million
More than 3.4 million people have fled Ukraine since Russia invaded, according to the latest figures from the United Nations High Commissioner for Refugees.
Monday's update showed that, of those refugees, more than 2 million have crossed the border into Poland. Additionally, about 535,000 have entered Romania and 365,000 have crossed into Moldova.
Refugees are also going to Hungary, Slovakia, Russia and Belarus.
People rest in a special room for refugees at a railway station in Lviv, western Ukraine, on March 21, 2022.
Yuriy Dyachyshyn/AFP via Getty Images
UNHCR chief Filippo Grandi tweeted Sunday that since the Russian invasion, 10 million people in Ukraine fled, either displaced in the country or as refugees abroad.
"Among the responsibilities of those who wage war, everywhere in the world, is the suffering inflicted on civilians who are forced to flee their homes," he wrote.
UNICEF told ABC News that half of the internally displaced Ukrainians and half of those who have fled are children.
-ABC News' Zoe Magee
Mar 21, 2022, 5:21 AM EDT
No surrender in besieged Mariupol, Ukraine says
Ukrainian officials rejected Russia’s demand that they surrender the southern port city of Mariupol on Monday morning.
“There can be no talk of any surrender, laying down of arms," Deputy Prime Minister Irina Vereshchuk said, according to The Associated Press.
Officials instead called on Russia to allow residents to evacuate safely from the city.
Service members of pro-Russian troops are seen atop of a tank during Ukraine-Russia conflict on the outskirts of the besieged southern port city of Mariupol, Ukraine March 20, 2022.
Alexander Ermochenko/Reuters
President Volodymyr Zelenskyy in an early morning video address said his government was preparing to send buses to Mariupol on Monday to continue the evacuation.
“In besieged Mariupol, Russian aircraft dropped a bomb on an art school. People were hiding there. Hiding from shelling, from bombing,” Zelenskyy said, according to an official translation from his office. “There were no military positions. There were about four hundred civilians. Mostly women and children, the elderly. They are under the debris. We do not know how many are alive at the moment.”
Some who’ve left Mariupol have described dire circumstances, with constant shelling and little access to essentials, including food, water, and medicine, according to a report published Monday by Human Rights Watch.
People dig a grave for victims killed during Ukraine-Russia conflict in the besieged southern port city of Mariupol, Ukraine March 20, 2022.
Alexander Ermochenko/Reuters
“Mariupol residents have described a freezing hellscape riddled with dead bodies and destroyed buildings,” Belkis Wille, senior crisis and conflict researcher at Human Rights Watch, said in a statement. “And these are the lucky ones who were able to escape, leaving behind thousands who are cut off from the world in the besieged city.”
Mar 20, 2022, 10:17 PM EDT
Biden traveling to Poland Friday to discuss efforts to support Ukraine, humanitarian crisis
In addition to his trip to Brussels, President Joe Biden will also travel to Warsaw, Poland, on Friday, where he will hold a bilateral meeting with President Andrzej Duda.
"The President will discuss how the United States, alongside our Allies and partners, is responding to the humanitarian and human rights crisis that Russia’s unjustified and unprovoked war on Ukraine has created," White House Press Secretary Jen Psaki said in a statement Sunday.
Psaki's statement did not specify if Biden will do anything else during his trip to Poland, which has taken in more than 2 million Ukrainian refugees since the start of the conflict with Russia.
