The US State Department has ordered most of its direct hire employees at the Embassy in Kiev to evacuate, suspending the regular consular services, "due to the continued threat of Russian military action".
In an updated travel advisory issued on Saturday, the State Department said passport, visa and other routine consular services will be suspended starting from Sunday, but the US will maintain a small consular presence in the western Ukrainian city of Lviv to handle emergencies, reports Xinhua news agency.
The update came two days after Washington urged all US citizens to leave Ukraine immediately.
US National Security Advisor Jake Sullivan told reporters on Friday at the White House that American nationals should evacuate within 48 hours, citing unspecified intelligence purporting a Russian invasion of Ukraine at any moment.
The State Department has been told in recent days that a "couple thousand" Americans are still in Ukraine, a "substantial number" of whom do not want to leave, a senior State Department official said during a call with reporters on Saturday.
Biden-Putin discuss Ukraine situation
On Saturday evening, US President Joe Biden and his Russian counterpart Vladimir Putin discussed situation in Ukraine and related security issues in a phone call that lasted for about an hour.
The White House said Biden made it clear to Putin "while the US remains prepared to engage in diplomacy", it is "equally prepared for other scenarios".
Kremlin aide Yuri Ushako said the two leaders have agreed to continue contacts and that Russia will soon submit its response to the US and NATO on security guarantees.
Earlier in the day, US Secretary of State Antony Blinken spoke to Russian Foreign Minister Sergey Lavrov over the phone, during which the top American diplomat reiterated "Russian aggression" would be met with a resolute and massive response.
On his part, Lavrov "stressed that the propaganda campaign launched by the US and its allies regarding 'Russian aggression' against Ukraine pursues provocative goals, encouraging the authorities in Kiev to sabotage the Minsk agreements and harmful attempts to resolve the 'Donbas problem' by force", the Russian Foreign Ministry said.
US Defense Secretary Lloyd Austin also held a phone conversation with his Russian counterpart, Sergey Shoigu, on Saturday.
(With inputs from IANS)
