Russia's President Vladimir Putin and US President Joe Biden spoke over the phone

While speaking to the US president over the phone, the Russian president termed such sanctions as a "colossal mistake".

Biden, on the other hand, told Putin that any invasion of Ukraine would lead the US and its allies to respond with measures which would not be welcome in Moscow.

The phone call, requested by Russia, lasted for two hours and it’s the second call the two have shared in the last month.

Biden and Putin both hope to defuse the potentially explosive situation over Ukraine's eastern border with Russia, where panic-stricken Ukrainian officials claim that more than 100,000 Russian troops have been deployed and seem poised to invade.

This build-up of Russian troops at Ukraine’s border has triggered alarm bells in the West, with the US threatening Russia’s Putin with sanctions "like none he's ever seen" if Ukraine is invaded.

Russia, however, says its troops are there on routine exercises and so it has no intention of invading Ukraine. Besides, it is free to move troops on its own soil, says Putin.

The Russian foreign policy adviser Yuri Ushakov told reporters shortly after the call between the two leaders that Putin was "pleased" with the conversation.

Ushakov went on to say the phone conversation was a "good backdrop" for future talks

"President Biden reiterated that substantive progress in these dialogues can occur only in an environment of de-escalation," White House Press Secretary Jen Psaki said.

"He made clear that the United States and its allies and partners will respond decisively if Russia further invades Ukraine," she added.

In Geneva next month, both sides will meet for in-person talks as they both continue to pursue a diplomatic solution.