MOSCOW/KYIV: US President Joe Biden said on Thursday there was now every indication Russia was planning to invade Ukraine in the next few days and was preparing a pretext to justify it, after Ukrainian forces and pro-Moscow rebels traded fire in eastern Ukraine.

The Kremlin accused Biden of stoking tension and released a strongly worded letter which said Washington was ignoring its security demands and threatened unspecified “military-technical measures”. Moscow also ejected the number two official from the US embassy.

Early morning exchanges of fire between Ukraine and pro-Russian separatists stoked alarm, with Western officials who have long warned that Moscow could try to create a scenario to justify an invasion saying they believed that was now unfolding.

Biden urges Americans to leave Ukraine as fears of Russian invasion mount

“We have reason to believe they are engaged in a false flag operation to have an excuse to go in. Every indication we have is they’re prepared to go into Ukraine and attack Ukraine,” Biden told reporters as he departed the White House.

“My sense is this will happen in the next several days.”

Biden ordered Secretary of State Antony Blinken to change his travel plans at the last minute to speak at a United Nations Security Council meeting on Ukraine.