US State Department official Derek Chollet has warned that the US will impose “crippling” sanctions on Russia if it invades Ukraine.

Such warning on Sunday came after a phone call between Russian President Vladimir Putin and US President Joe Biden ended with no breakthrough on the crisis.

The White House insists Moscow faces “swift and severe costs” if it pushes ahead with aggression, while the Kremlin has denounced the US’s “peak hysteria” over the Ukraine conflict and has denied it has plans to invade.

Meanwhile, US Secretary of State Antony Blinken said the risk of Russian military action in Ukraine was high enough to justify the departure of much of the staff at the US embassy in Kyiv, but said a diplomatic solution to the crisis is still possible.

“The diplomatic path remains open. The way for Moscow to show that it wants to pursue that path is simple. It should de-escalate rather than escalate,” he said.