Washington announces its readiness for Russia's diplomacy or aggression, and Kiev calls for calm

US Secretary of State Anthony Blinken said Washington was ready for diplomacy or "aggression" by Moscow in the Ukraine crisis, while Kiev urged its citizens to remain calm and not panic in the face of the Russian threat.

US Secretary of State Anthony Blinken said he would speak with his Russian counterpart Sergei Lavrov on Saturday, adding that Washington was ready for diplomacy or "aggression" by Moscow in the Ukraine crisis.

US President Joe Biden and his Russian counterpart Vladimir Putin will speak on Saturday, as Western countries warn of a war in Ukraine at any moment.

Blinken told reporters in Fiji that if Putin was really keen on resolving the escalating crisis diplomatically, Washington was ready to play its part, but would impose quick economic sanctions if Moscow invaded Ukraine.

"I still hope that he will not choose the path of renewed aggression and that he will choose the path of diplomacy and dialogue," he added during a press conference after a meeting with leaders of Pacific countries.

"But if he doesn't, we are ready," he added.

"If President Putin decides to carry out military action, we will promptly impose tough economic sanctions in coordination with allies and partners around the world, we will strengthen Ukraine's ability to defend itself and we will support our allies on the eastern side of NATO," Blinken said.

He indicated that he would ask Lavrov about the Russian response to the American proposals to solve the crisis.

On Saturday, Ukraine urged its citizens to remain calm and not panic in the face of growing fears that Russia is preparing to invade its neighbour.

This call comes a day after the United States and a number of European countries called on their citizens to leave Ukraine immediately due to the increasing threat of a major Russian attack targeting the former Soviet republic.

"At this stage, it is extremely important to remain calm, strengthen the country internally and avoid actions that destabilize the situation and sow panic," the Ukrainian foreign ministry said in a statement.

On Friday, Washington raised concerns that Russia could launch an attack "any day from now".

Some media speculated that the incursion would begin shortly after German Chancellor Olaf Scholz ended his talks with Russian President Vladimir Putin in Moscow on Tuesday.

Since the outbreak of the crisis, Kiev has been seeking to soften the warnings issued by Washington.

The Ukrainian government fears that the US statements will dampen public morale and harm the faltering economy, by paralyzing business activities.

"The Ukrainian armed forces are constantly monitoring the situation and are ready to confront any encroachment on its territorial integrity and sovereignty," the foreign ministry said.

"Ukrainian diplomats are in constant contact with all major partners and quickly receive the information necessary to prepare a timely response," she added.