More than a dozen countries have urged their citizens to leave Ukraine amid warnings from Western powers that an invasion by Russia could be imminent.
The US, UK and Germany are among those who told their nationals to leave.
Moscow has amassed an estimated 100,000 troops along Ukraine’s border but denies any intent to invade.
Ukraine’s President Volodymyr Zelensky said on Saturday that invasion warnings could stoke panic, which he called “the best friend of our enemies”.
The White House has warned that an invasion could happen at any time, and could begin with bombing from the air. Russia characterised such allegations as “provocative speculation”.
Non-essential staff have been ordered to leave the US Embassy in Ukraine’s capital Kyiv, and consular services will be suspended from Sunday, although “a small consular presence” will remain in the western city of Lviv “to handle emergencies”.
Canada is also moving its embassy staff to Lviv, near the border with Poland, Canadian media reported. UK ambassador to Ukraine Melinda Simmons tweeted that she and a “core team” are staying in Kyiv.
Russia itself is also making changes, saying it will “optimise the staffing” of its diplomats in Ukraine, citing “possible acts of provocation by the Kyiv regime or third countries”.
The US has also pulled some 150 troops who were training Ukrainian soldiers out of the country, citing an abundance of caution. And Dutch airline KLM announced it would stop flying to Ukraine, effective immediately, Dutch media said.
Mr Zelensky said that if Western powers had any firm evidence of an impending invasion, he had yet to see it.
“I think there is too much information in the media about a deep, full-scale war,” he said.
“We understand all the risks, we understand that they exist. If you or someone else has additional 100% reliable information about the Russian Federation’s invasion of Ukraine… please share it
Many countries, including Australia, Italy, Israel, the Netherlands and Japan have told their citizens to leave Ukraine. Some have also evacuated diplomatic staff and their families.
Diplomatic efforts are continuing on multiple fronts. US President Joe Biden spoke to Russian leader Vladimir Putin for more than an hour. US officials told Reuters news agency the call was “professional” but had produced no fundamental change.
Mr Biden told his counterpart that any invasion would result in “swift and severe costs on Russia”, White House notes about the call said.
“While the United States remains prepared to engage in diplomacy… we are equally prepared for other scenarios,” it said.
French President Emmanuel Macron also spoke to Mr Putin by phone on Saturday, telling him that “a sincere dialogue was not compatible with escalation”, according to notes released by the French embassy.