Tensions have risen in recent months over Ukraine, which the West accuses Russia of planning an imminent military attack on it.
A row has erupted between Kiev and Moscow since Russia annexed Ukraine's Crimea peninsula in 2014, and a war ensued in eastern Ukraine with pro-Russian separatists.
The following is a timeline of the latest escalation between the West and Russia over Ukraine:
military moves
On November 10, 2021, Washington requested clarifications from Russia regarding the "extraordinary" movements of its forces on the Ukrainian border, and in April Moscow had mobilized about 100,000 soldiers on the border.
Russian President Vladimir Putin has accused the West of delivering weapons to Kiev and conducting "provocative" military exercises in the Black Sea and near the border.
On November 28, Ukraine confirmed that Russia had massed some 92,000 troops on its border.
On the other hand, the Russian authorities accused Ukraine of massing its forces in the east of the country.
Summit between Biden and Putin
On December 7, US President Joe Biden threatened Russian President Vladimir Putin with "severe economic sanctions" if he invaded Ukraine, during a virtual bilateral summit.
Moscow revealed two draft treaties that prohibit any expansion of the North Atlantic Treaty Organization (NATO), especially the annexation of Ukraine, as well as the withdrawal of NATO forces from the countries of the former Soviet Union.
Troops on alert
On January 18, after fruitless talks in Geneva and then in Brussels, Moscow deployed troops to Belarus.
Washington allocated an additional $200 million in security assistance to Ukraine and allowed the Baltic states to hand over American weapons to Kiev.
On January 24, NATO announced that it was sending ships and combat aircraft to reinforce its defenses in Eastern Europe, and Washington put up to 8,500 soldiers on alert.
The Kremlin accused Washington of causing "exacerbation of tension", and soon after held new exercises near Ukraine and in the Crimea.
Moscow's demands were rejected
On January 26, the United States rejected Moscow's basic demands.
Russian and Ukrainian envoys met in Paris, the French and German mediators, in an effort to restart the peace process in eastern Ukraine.
Beijing next to Moscow
On January 27, China backed Moscow's "reasonable security concerns."
On February 2, Washington sent an additional 3,000 troops to Eastern Europe to defend NATO member states.
On February 7, Vladimir Putin said he was ready for "compromises" after a long meeting in the Kremlin with French President Emmanuel Macron, whose country holds the European Union's rotating presidency.
On February 10, Russian and Belarusian forces began major exercises in Belarus.
The specter of war in Europe
On February 11, NATO insisted that there was a “real danger of a new armed conflict” in Europe, while several countries called on their nationals to leave Ukraine as soon as possible.
For the Kremlin, the previous day's discussions of Russia, Ukraine, Germany and France in Berlin had "no result".
The United States confirmed that the Russian invasion of Ukraine could happen "at any time", and decided to send an additional 3,000 troops to Poland.
chain of communication
On February 12, Ukraine considered US warnings of a possible Russian invasion "panic."
Moscow, which started new naval exercises in the Black Sea, announced that it would reduce the number of its diplomatic staff there.
Biden has warned his Russian counterpart of "significant and immediate costs" to Moscow if Russia invades Ukraine.
On February 13, Biden and his Ukrainian counterpart agreed to continue "diplomacy" and "deterrence" against Moscow.
German Chancellor Olaf Schulz has warned that Western sanctions would be "immediate" if Russia invaded Ukraine.
On the edge of the abyss
On February 14, the United States decided to move its embassy from Kiev to the western city of Lviv.
British Prime Minister Boris Johnson called on Russian President Vladimir Putin to step back from "the brink of the abyss", saying that the situation was "very dangerous".
Russian Foreign Minister Sergei Lavrov offered President Vladimir Putin an "extension and expansion" of dialogue with Westerners.
Withdrawal or consolidation of presence?
On February 15, the Kremlin confirmed the start of a "partial withdrawal" of Russian forces stationed near the Ukrainian border.
On February 16, NATO announced that it did not see any sign of reducing tension, stressing, like Washington, that Moscow, on the contrary, was seeking to strengthen its military presence.
Heavy gunfire escalated along the front line between pro-Russian separatists and Ukrainian forces.
Biden warned that Russia may launch an attack "in the coming days", while Moscow has deployed 150,000 troops on the Ukraine border, according to US intelligence.
In return, Moscow announced a military withdrawal.
On February 19, Ukrainian President Volodymyr Zelensky offered to meet with Putin, who was meanwhile overseeing "strategic" exercises involving the launch of hypersonic missiles.
Washington announced that Russian forces were "preparing to launch a strike", while France and Germany urged their citizens to leave Ukraine.
On February 20, Belarus announced the continuation of joint military exercises with Russia on its territory.
Putin recognizes the independence of Ukrainian separatists
On February 21, the Elysee Palace announced that the Russian and American presidents had agreed in principle to his offer of a summit, but the Kremlin considered such a meeting "premature."
The Russian army announced that it had killed 5 saboteurs from Ukraine and captured a Ukrainian soldier, an accusation denied by Kiev.
Putin considered that the peace process in the conflict in Ukraine has no chances, while Kiev announced the killing of two Ukrainian soldiers and a civilian in shelling carried out by separatists.
Putin announced Russia's recognition of the independence of the breakaway regions of Donetsk and Luhansk in eastern Ukraine, in a speech on state television, despite warnings from the West that it would subject Russia to severe sanctions.
State television broadcast footage showing Putin signing cooperation agreements with the leaders of the two regions in the Kremlin.
The Russian president ordered his army to enter the separatist lands in eastern Ukraine.
Putin issued two decrees instructing the Ministry of Defense that “the Russian Armed Forces shall undertake the peacekeeping mission on the territory of the Donetsk and Lugansk People’s Republics.