Washington: US President Joe Biden and his Russian counterpart Vladimir Putin had a “professional and substantive” phone conversation on Saturday, but there has been no change in the fundamental dynamics of Russian escalation along Ukraine’s borders and there remains a possibility of Russian invasion, according to a senior US administration official.

A statement from White House, on the telephonic conversation read- “Russia’s escalating military buildup” and was clear that if Russia undertook a “further invasion” of Ukraine, the US – along with allies and partners – would “respond decisively” and “impose swift and severe costs” on Russia. Kremlin after the one hour long call, denounced US “peak hysteria” surrounding the Ukraine conflict but said Russian President Vladimir Putin and US leader Joe Biden had agreed to continue dialogue.

The call between the two leaders took place hours after Washington evacuated most of its embassy in Kyiv and pulled out a small contingent of 140 troops from the Florida National Guard from the country, saying Russian invasion could take place within days, if not hours. The US officials seem to believe Moscow will press ahead with the attack, with Wednesday cited as the likely day for a Russian invasion. The administration kept leaking intelligence, it claimed, pointed to a Russian attack, through the day.