The United States said Monday it is suspending operations at its embassy in Belarus and allowing the departure of non-emergency staff from the American Embassy in Moscow.
"We took these steps due to security and safety issues stemming from the unprovoked and unjustified attack by Russian military forces in Ukraine," Secretary of State Antony Blinken said in a statement.
Belarus is a Russian ally that allowed its territory to be used as a staging ground for the attack on Ukraine.
In a referendum held Sunday, Belarusians voted to allow the country to host nuclear weapons and Russian forces permanently, results showed Monday. This was part of a package of constitutional reforms that also extended the rule of leader Alexander Lukashenko.
"We ultimately have no higher priority than the safety and security of U.S. citizens, and that includes our U.S. government personnel and their dependents serving around the world," Blinken's statement said.
The United States already closed its embassy in Kyiv as Russia prepared the invasion and has been calling for weeks for American citizens in Ukraine to get out.
A small team of U.S. diplomats is handling embassy affairs from the western city Lviv, near the border with Poland.
In mid-February, the U.S. State Department also urged Americans in Belarus to leave that country.
The U.S. Embassies in the Belarus capital Minsk and Moscow were already operating at a reduced level because of tit-for-tat diplomat expulsions going back several years.