Employees of US embassy in Ukraine raise the US national flag at the US embassy in Kyiv.
(Picture: AP)All US citizens still in Ukraine have been told to depart the country immediately as Russian forces line up fresh strikes.
The American embassy in Kyiv gave the warning on Monday amid reports that Vladimir Putin’s forces will launch their next offensive on Wednesday - on Ukraine’s independence day.
The State Department said Russia would increasingly target Ukrainian civilian infrastructure.
A statement told remaining US citizens: “If you hear a loud explosion or if sirens are activated, immediately seek cover.
"If in a home or a building, go to the lowest level of the structure with the fewest exterior walls, windows, and openings; close any doors and sit near an interior wall, away from any windows or openings."
The US warning came after Russia claimed that Ukrainian intelligence was responsible for a weekend car bombing outside Moscow that killed the daughter of a leading right-wing Russian political theorist. Ukraine denied involvement.
Hundreds of people lined up at a memorial service to pay tribute to Darya Dugina, 29, the daughter of Alexander Dugin, a nationalist writer whom the media have dubbed "Putin's brain" and "Putin's Rasputin" due to his purported influence on the Russian President.
Ms Dugina, a commentator with a Russian TV channel, died when the SUV she was driving blew up on Saturday night as she was driving home from the patriotic Tradition festival.
Her father, a philosopher firmly behind Mr Putin's decision to send troops into Ukraine, was widely believed to be the intended target.
Ukrainian leader Volodymyr Zelenskyy said a “powerful response,” would meet any Russian insurgence. “This response will grow, it will get stronger and stronger,” he added.
