According to a White House official, the phone call had begun at 11:04 am ET (16:04 GMT) and the one hour and two minutes long telephonic conversation between the two leaders ended at 12:06 pm ET (17:06 GMT).

The discussion between Biden and Putin came hours after the US moved some of its forces out of Ukraine and ordered the evacuation of most of its embassy staff on Saturday as a tense world worried that a Russian invasion of Ukraine could begin within days.

Following the telephonic conversation between the two Presidents, the White House said Biden told Putin the United States will "impose swift and severe costs on Russia" if Ukraine invasion takes place.

"President Biden spoke with President Vladimir Putin today to make clear that if Russia further invades Ukraine, the U.S. and our allies will impose swift and severe costs on Russia. President Biden urged President Putin to engage in de-escalation and diplomacy instead," the White House tweeted.

"President Biden was clear that, if Russia undertakes a further invasion of Ukraine, the United States together with our Allies and partners will respond decisively and impose swift and severe costs on Russia," according to a statement released by the White House.

"President Biden reiterated that a further Russian invasion of Ukraine would produce widespread human suffering and diminish Russia’s standing," read the media release.

"President Biden was clear with President Putin that while the United States remains prepared to engage in diplomacy, in full coordination with our Allies and partners, we are equally prepared for other scenarios," it added.

As fears mount that a Russian invasion of the country could take place at any time, the US has announced plans to evacuate its embassy in the Ukrainian capital of Kiev, and Britain joined other European nations in urging its citizens to leave Ukraine, which is clearly a sign that American and other European countries' officials are getting ready for a worst-case scenario.

Sources said, before talking to Biden, Vladimir Putin had a phone call with French President Emmanuel Macron, who met with him in Moscow earlier this week in an attempt to 'cool down' the biggest security crisis between Russia and the West since the Cold War.

Emmanuel Macron, Vladimir Putin held talks on Ukraine and other issues earlier this week. Image from Twitter/President of Russia (@KremlinRussia_E)

"In the follow-up to the discussions during President Macron’s recent visit to Moscow, the two leaders had an in-depth exchange of opinions on the issues related to ensuring long-term legal security guarantees for the Russian Federation and overcoming the stalemate in settling the intra-Ukrainian conflict, including in view of Emmanuel Macron’s conversations with the leaders of Ukraine, the United States and a number of European states," according to a Kremlin statement following the Putin-Macron conversation.

"Vladimir Putin and Emmanuel Macron also discussed the situation concerning provocative speculations regarding the allegedly planned Russian 'invasion' of Ukraine, which is accompanied by massive supplies of modern weaponry to Ukraine, thus creating conditions for possible aggressive actions by the Ukrainian military in Donbass," the statement read.

Meanwhile, the Russian Ministry of Foreign Affairs has accused Western countries and the media of spreading a "large-scale disinformation campaign" about an allegedly impending Russian invasion of Ukraine.

It alleged the Western governments and the press have been running the "unprecedented" campaign against Russia "in order to divert attention from their own aggressive actions."

"Late 2021 – early 2022 has seen a global media campaign that is unprecedented in scale and sophistication, the aim of which is to convince the world public that the Russian Federation is preparing to invade Ukraine," according to a press statement by the Russian Ministry of Foreign Affairs.

"The Western media have been spreading outright disinformation, trying to manipulate the public into believing that Moscow has aggressive intentions. In the process, they have ignored the detailed, reasoned explanations of Russian officials who have assured the public many times that Russia is committed to the peaceful diplomatic settlement of the crisis in Ukraine along the lines of the Minsk Package of Measures," the statement read.

Meanwhile, Ukraine's Defence Minister Oleksiy Reznikov said Saturday that the country's armed forces were absolutely ready to fight back and will not allow capture of any Ukrainian cities if Russia — which he described as “the aggressor” — attempts to invade the country.

File image of Ukrainian Defence Minister Oleksiy Reznikov from his Twitter account (@oleksiireznikov)

"Everyone who has looked into the eyes of our soldiers at least once is sure that there will be no repeat of 2014, the aggressor will not capture either Kyiv, Odessa, Kharkiv or any other city,” the Ukrainian Defence Minister said.

The Ukrainian capital of Kiev on Saturday witnessed a "March of Unity for Ukraine" from Shevchenko Park to Maidan Square, also known as Independence Square, where thousands took part carrying Ukraine's flags and signs with pro-Ukrainian slogans.

Russia has reportedly stationed more than 100,000 troops near its border with Ukraine and has sent the military personnel to exercises in neighboring Belarus amid rising tensions between the two countries.

Image: UNI

Moscow, however, denies that it intends to launch an offensive against Ukraine and claims its troops are in the region for military drills.

The border tensions come nearly eight years after Russia annexed Ukraine's southern Crimea peninsula and backed a bloody rebellion in the eastern Donbas region, while Moscow has accused the Ukrainian government of failing to implement the Minsk agreement, which sought to end war in the Donbas region of Ukraine.