Washington orders departure of eligible family members of staff from its embassy in Ukraine and warns Americans not to travel to Russia due to mounting tensions on border with Ukraine.
The United States has ordered the families of its diplomats in the Ukrainian capital Kiev to leave the country "due to the continued threat of Russian military action."
On Sunday, Washington also authorised the "voluntary" departure of its embassy employees and urged US citizens in the Eastern European country to "consider departing now using commercial or other privately available transportation options."
The security situation around Ukraine''s borders, in Russia-occupied Crimea, and in Russia-controlled eastern Ukraine are unpredictable and can deteriorate with little notice, said the statement, adding there are reports that Russia is planning significant military action against Ukraine.
US also issued a travel advisory warning Americans not to travel to Russia due to mounting tensions on the border with Ukraine.
"Do not travel to Russia due to ongoing tension along the border with Ukraine," a statement said, adding Americans could also face "harassment" and that the embassy would have "limited ability to assist US citizens."
It particularly moved to dissuade US citizens from traveling to the Russia-Ukraine border region, saying "the situation along the border is unpredictable and there is heightened tension," due to a Russian troop build up and military exercises in the area.
The State Department announcement comes amid tensions between Russia and the West over European security and concerns over a possible invasion by Moscow of Ukraine.
Russia has been massing tens of thousands of troops on its border with Ukraine, along with an arsenal of tanks, fighting vehicles, artillery and missiles.
Moscow denies claims it wants to invade its neighbour, a Western ally.
The movements have ignited stern warnings from Washington and Europe –– but so far intense diplomacy has yielded little results.
READ MORE: US embassy staff families evacuate Ukraine
US won't slap sanctions as of now
Earlier on Sunday, US Secretary of State Antony Blinken dismissed the idea of slapping punitive sanctions on Moscow before any potential invasion, saying they should be used as a means of "dissuading" an attack.
"Once sanctions are triggered, you lose the deterrent effect," Blinken told CBS.
"So what we're doing is putting together a whole series of actions that would figure into President (Vladimir) Putin's calculus."
That includes beefing up defences in Ukraine with more military assistance, Blinken said.
Russian forces have also amassed in ally Belarus, just north of Ukraine. The Kremlin has maintained that there too troops are taking part in exercises. It has also been steadily building up its force levels in Crimea.
Russia in 2014 annexed Ukraine's Crimean Peninsula in a move that has never been met with international recognition, and which has been decried as illegal under international law.
That year also saw Moscow begin its support for separatist rebels in eastern Ukraine, a policy it has continued for eight years.
According to the UN, fighting between Ukrainian government forces and pro-Russian separatists in eastern Ukraine has seen more than 13,000 people killed since 2014.