Timeline of the prelude to the Russian invasion of Ukraine

This timeline of the prelude to the Russian invasion of Ukraine covers a period of heightened tensions between Russia and Ukraine from early 2021 until the start of the Russian invasion of Ukraine on 24 February 2022.

2021

 * 2 September – Russia refuses to extend the mandate of the Organization for Security and Co-operation in Europe mission at the Gukovo and Donetsk border checkpoints from 30 September onward.
 * 11 November – The United States reports an unusual movement of Russian troops near the borders of Ukraine. By 28 November 2021, Ukraine has a reported build-up of 92,000 Russian troops.
 * 7 December – US President Joe Biden warns President of Russia Vladimir Putin of "strong economic and other measures" if Russia attacks Ukraine.
 * 17 December – Russian President Vladimir Putin proposes a prohibition on Ukraine joining NATO, which Ukraine rejects.

January

 * 17 January – Russian troops begin arriving in Russia's ally Belarus, ostensibly "for military exercises".
 * 19 January – The US gives Ukraine $200 million in security aid.
 * 19 January – President Biden states in a press conference: "Russia will be held accountable if it invades. And it depends on what it does."
 * 24 January – NATO puts troops on standby.
 * 25 January – Russian exercises involving 6,000 troops and 60 jets take place in Russia near Ukraine and Crimea.

February

 * 10 February – Russia and Belarus begins 10 days of military maneuvers.
 * 17 February – Fighting escalates in separatist regions of eastern Ukraine.
 * 21 February – Vladimir Putin ordered Russian forces to enter the separatist republics in eastern Ukraine. He also announced Russian recognition of the two pro-Russian breakaway regions in eastern Ukraine (the Donetsk People's Republic and the Luhansk People's Republic). This announcement led to the first round of economic sanctions from NATO countries the following day.

In Putin's televised "address concerning the events in Ukraine" before the announcement, he stated his belief that Vladimir Lenin was the "author and architect" of Ukraine and labelled Ukrainians who had taken down Lenin's monuments "ungrateful descendants", saying "This is what they call decommunization. Do you want decommunization? Well, that suits us just fine. But it is unnecessary, as they say, to stop halfway. We are ready to show you what real decommunization means for Ukraine."