The U.S. Embassy in Kyiv has warned of increased Russian military strikes on Ukraine ahead of the latter’s independence day.
A statement on its website advised Americans to leave the country if safe to do so.
It said the Department of State has information that Russia is stepping up efforts to launch strikes against civilian infrastructure and government facilities.
The Embassy urged U.S. citizens “to depart Ukraine now using privately available ground transportation options”.
Ukrainian authorities have banned public celebrations in Kyiv as the nation marks independence from Soviet rule on Wednesday.
Ukraine said Russia fired rockets into towns north and west of Europe’s largest nuclear power plant captured in late February.
There are fears that consecutive shelling of locations near the Zaporizhzhia nuclear reactor complex would cause a major disaster.