Russia-Ukraine war: Key events in 2nd year of Russia's invasion of Ukraine

Russian President Vladimir Putin announced on Feb. 21, 2022, that he had recognized two Russian-backed separatist areas in eastern Ukraine, Donetsk and Luhansk, as independent states.

Ukrainian President Volodymyr Zelenskyy followed the announcement by saying that Ukraine had cut diplomatic ties with Russia. Putin then gave a speech on Feb. 24, 2022, announcing he would launch a "special military operation" in Ukraine.

Minutes after the announcement, explosions could be heard in Kyiv. What followed was a full-scale invasion of Ukraine, with thousands of troops crossing the country's borders.

Two years later, the war is still ongoing. Here are a few key events from the last 12 months.

Wall Street Journalist is detained in Russia

Wall Street Journal reporter Evan Gershkovich was arrested and detained by Russian authorities in March on espionage charges, allegations that Gershkovich, the WSJ, the U.S. government and dozens of international news organizations have vehemently denied.

He's since appealed his pretrial detention, appearing several timesin Moscow courtrooms.

Alsu Kurmasheva, a journalist with Europe/Radio Liberty, was also detained in October and charged with failure to register as a foreign agent, according to the news outlet on Wednesday. Kurmasheva, who serves as an editor for the outlet's Tatar-Bashkir Service, is a dual U.S.-Russian citizen, RFE/RL said.

Both Geshkovich and Kurmasheva remain in pre-trial detention in Russia.

"Next month will mark one year since Evan’s arrest and wrongful detention -- a milestone that was once unthinkable for his family, friends and his colleagues," Almar Latour, CEO of Dow Jones and publisher of The Wall Street Journal, and Emma Tucker, Wall Street Journal Editor in Chief, said in a statement this month.

They added, "As we have said since day one and will for as long as it takes -- we continue to demand his immediate release and will not rest until he is home."

Ukraine begins long-awaited counteroffensive

After weeks of anticipation, Ukraine began its long-awaited counteroffensive against Russia in mid-June, local officials told ABC News.

Western officials said at the time that Russia’s forces in Ukraine were so badly depleted that Russia may lack the reserves to effectively respond to a major counteroffensive from Ukrainian troops.

Russian paramilitary leader Yevgeny Prigozhin led a 1-day rebellion

A chaotic armed rebellion that threatened the longstanding leadership of Putin began on a Friday in late June 2023. It was quelled by Saturday evening.

The uprising, led by Yevgeny Prigozhin, chief of the paramilitary Wagner Group, began in the southern Russian city of Rostov-on-Don. Forces loyal to Prigozhin marched toward Moscow, before turning back Saturday night.

Prigozhin was on the passenger list of a plane that crashed in August in Russia's Tver region, killing all on board.

Counteroffensive progress was slow, but not a 'stalemate,' a US official said

White House national security adviser Jake Sullivan said Sunday that the war in Ukraine hasn't devolved into a stalemate but he acknowledged it remains "hard going" against Russia.

"We said before this counteroffensive started that it'd be hard going, and it's been hard going," Sullivan said in an interview with ABC News "This Week" anchor George Stephanopoulos, referring to a new push by the Ukrainians that began this summer. "That's the nature of war, but the Ukrainians are continuing to move forward."

Zelenskyy tells ABC News the counteroffensive may force Putin into a dialogue

In a sit-down in July with ABC News' Chief Global Affairs Correspondent Martha Raddatz that aired on "This Week," President Volodymyr Zelenskyy described the current situation.

"Well, it is absolutely clear, logical rhetoric that at that moment when Ukraine will reach the administrative border with a temporarily occupied Ukrainian peninsula, Crimea, it's very likely that Putin will be forced to seek dialogue with the civilized world, unlike how it was before the full-scale invasion, because he will be weakened," Zelenskyy said.

Ukraine took heavy casualties in its counteroffensive

There is mounting evidence that Ukraine has been taking heavy casualties in its counteroffensive, which began roughly ten weeks ago.

ABC News spoke with two former U.S. soldiers who are contracted in a special forces division of the Ukrainian military and who were both injured during an operation in eastern Ukraine two weeks ago.

Both soldiers are currently in a hospital in Kyiv but said they hope to be transferred to Germany for surgery this week in order to remove shrapnel from their bodies.

At the 2-year mark

The U.S. Congress remains deadlocked on further military aid, as Ukrainian officials have for months raised alarms about the military's dwindling stockpile.

The U.S. has supplied at least $44.9 billion to Kyiv, but if Congress doesn't pass a new aid package by late spring or early summer, the situation in Ukraine could become dire, U.S. officials told ABC News.

Read the timeline of the first year of the war here.

ABC News' Nadine El-Bawab, Joe Simonetti, Patrick Reevell, Luis Martinez, Jon Haworth, Jolie Lash, Shannon K. Crawford, Fritz Farrow, Guy Davies, Tom Soufi Burridge, Oleksiy Pshemyskiy, Ibtissem Guenfoud, Kuba Kaminski, Anne Flaherty and Yulia Drozd contributed to this story.