The announcement came after the US issued a public warning for all American citizens in Ukraine to leave the country as soon as possible, adding Russia could invade Ukraine any day now.
The US State Department has ordered non-emergency US embassy staff to leave Ukraine amid rising tensions with Russia.
They were told to depart "due to continued reports of a Russian military build-up on the border with Ukraine, indicating potential for significant military action," the US Embassy in Kiev said on Saturday.
Earlier, US officials, speaking on the condition of anonymity, said a small number of the diplomats may be relocated to Ukraine’s far west, near the border with Poland.
The State Department had earlier ordered families of US embassy staffers in Kiev to leave. But it had left it to the discretion of nonessential personnel if they wanted to depart.
Meanwhile, US Secretary of State Antony Blinken said he would speak to Russian counterpart Sergey Lavrov on Saturday in a last-ditch attempt to head off a possible invasion.
"We continue to see very troubling signs of Russian escalation, including new forces arriving around Ukraine's borders," Blinken said in a press conference in Fiji.
The top US diplomat reiterated that Washington and its allies will "swiftly" impose punishing sanctions on Russia if it invades Ukraine, which he said could now start "at any time".
Despite the reduction in diplomatic staff, the core embassy team, our dedicated Ukrainian colleagues, and @StateDept and U.S. personnel around the world will continue relentless diplomatic and assistance efforts in support of Ukraine’s security, democracy, and prosperity.— U.S. Embassy Kyiv (@USEmbassyKyiv) February 12, 2022
Biden to speak with Putin
US President Joe Biden will also speak to Vladimir Putin on Saturday, according to a US official.
White House National Security Advisor Jake Sullivan dramatically raised the alarm over Ukraine on Friday, saying a Russian invasion starting with civilians caught under aerial bombing could begin in days.
He told US citizens to leave within 48 hours.
The Pentagon also announced on Friday it is sending another 3,000 combat troops to Poland to join 1,700 who already are assembling there.
Their mission will be to train and provide deterrence but not to engage in combat in Ukraine.
In addition to the US troops deploying to Poland, about 1,000 US soldiers based in Germany are shifting to Romania in a similar mission of reassurance to a NATO ally.
Also, 300 soldiers of an 18th Airborne Corps headquarters unit have arrived in Germany, commanded by Lieutenant General Michael Kurilla.
The American troops are to train with host-nation forces but not enter Ukraine for any purpose.