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 19, 2022, 6:26 AM EDT
Russia declares new phase of Ukraine invasion
Russia is starting the next phase of its "special military operation" in neighboring Ukraine, according to Russian Foreign Minister Sergey Lavrov.
"This operation will continue. Another stage of this operation is beginning," Lavrov said in an interview Tuesday with English-language Indian television network India Today. "I am sure this will be a very important moment of this entire special operation."
Lavrov noted that the goal of the operation is to "fully liberate" the Russian-backed separatist regions of eastern Ukraine's Donetsk and Luhansk oblasts, "as it was declared from the very start."
Apr 19, 2022, 6:16 AM EDT
Russia-backed separatist forces try to storm Azovstal plant in Mariupol
Russia-backed separatist forces are trying to storm a steel plant in besieged Mariupol where Ukrainian troops are holed up, according to separatist spokesperson Eduard Basurin.
Basurin, spokesman of the militia for a pro-Russia breakaway republic of Donetsk in eastern Ukraine's disputed Donbas region, told Russian state media on Tuesday that a separatist special forces unit was chosen to assist the Russian military in storming the giant plant of the Azovstal Iron and Steel Works company in Mariupol, a strategic port city in eastern Ukraine's war-torn Donetsk Oblast that has been under heavy Russian bombardment since the start of the invasion on Feb. 24.
Basurin said they have already started their operation at the Azovstal plant, with Russian forces providing air and artillery support.
Smoke rises above Azovstal steelworks, in Mariupol, Ukraine, in this still image obtained from a recent drone video posted on social media.
Mariupol City Council via Reuters
The territory of the Azovstal plant is the last holdout for the Ukrainian resistance in Mariupol, as Russian forces accelerate their efforts to capture city. The Mariupol City Council has previously said there are at least 1,000 people, including Ukrainian troops, on the grounds of the plant. Ukrainian Deputy Prime Minister Iryna Vereshchuk said Monday that civilians, including women and children, are also sheltering there and she called for an "urgent humanitarian corridor" to allow them to evacuate.
A few thousand Ukrainian troops, by Russia's estimate, remained holed up at a mammoth steel mill in Mariupol, the last known pocket of resistance in the devastated southern port city, on April 18, 2022.
AP
The Ukrainian government did not immediately confirm Tuesday that Russian forces are storming the Azovstal plant.
-ABC News' Yulia Drozd
Apr 19, 2022, 6:14 AM EDT
Ukraine says Russia is stepping up attacks in the east
Ukrainian military spokesperson Oleksandr Shtupun said Tuesday that Russian forces are stepping up attacks in the east.
Russian forces are currently focused on breaking through Ukrainian defences in the eastern Donetsk and Luhansk oblasts, as well as establishing full control over the strategic port city of Mariupol, according to Shtupun.
Servicemen of the Donetsk People's Republic militia look at bodies of Ukrainian soldiers placed in plastic bags in a tunnel, part of the Illich Iron & Steel Works Metallurgical Plant, the second largest metallurgical enterprise in Ukraine, in an area controlled by Russian-backed separatist forces in Mariupol, Ukraine, April 18, 2022.
Alexei Alexandrov/AP
In the south, Russian forces are focused on reaching the administrative border of the Kherson Oblast while continuing to shell the city of Mykolaiv, Shtupun said.
Meanwhile, Belarus continues to provide its territory to Russia for reconnaissance and launching air strikes against Ukraine. The Ukrainian cities of Kharkiv, Dnipro, Mykolaiv and Kherson were all shelled overnight, according to Shtupun.
-ABC News' Yulia Drozd
Apr 19, 2022, 5:33 AM EDT
Russian military calls on Ukrainian troops in Mariupol to surrender
The Russian military is calling on Ukrainian troops in besieged Mariupol to surrender by midday on Tuesday.
Russian forces have been trying to seize the strategic port city in eastern Ukraine's war-torn Donetsk Oblast since the start of the invasion on Feb. 24. The Russian Ministry of Defense said it is ready to declare a temporary ceasefire in Mariupol on Tuesday from 1:30 p.m. local time.
Ukrainian troops holed up on the grounds of the Azovstal iron and steelworks plant in Mariupol have until 12 p.m. local time to stop all fighting and lay down their arms, according to Col. Gen. Mikhail Mizintsev, head of Russia's National Defense Control Center. Moscow has proposed this plan "given the catastrophic situation in the Azovstal Iron and Steel Works, as well as for purely humanitarian considerations," Mizintsev told Russian state media on Tuesday.
A satellite image shows an overview of Azovstal Iron and Steel Works in Mariupol, Ukraine, April 9, 2022.
Maxar Technologies via Reuters, FILE
"All those who will lay down arms are guaranteed that their lives will be spared," he added. "The actual start of the temporary ceasefire shall be marked by both sides by raising flags -- red flags by the Russian side and white flags by the Ukrainian side along the entire perimeter of Azovstal. Furthermore, their readiness to put the temporary ceasefire into effect shall be confirmed by the sides via all communication channels."
According to Mizintsev, "absolutely all" Ukrainian troops and foreign mercenaries will be allowed to leave the plant without any weapons or ammunition from 2 p.m. to 4 p.m. local time. Moscow guarantees to each Ukrainian soldier who surrenders that their life will be spared and their rights as prisoners of war will be respected, Mizintsev said.
