Ukraine tensions: Russia looking for excuse to invade, US says

US Secretary of State Antony Blinken later told the United Nations Security Council that Russia was readying such a move.

He said it was not clear what form a pretext for an attack could take, but that possibilities include “a fabricated so-called terrorist bombing inside Russia, the invented discovery of a mass grave, a staged drone strike against civilians, or a fake – even a real – attack using chemical weapons”.

In the aftermath of such an incident, Mr Blinken said Russia’s government would likely “theatrically convene” an emergency meeting about protecting ethnic Russians in Ukraine – and Russian missiles and bombs would begin striking Ukrainian targets, alongside cyber-attacks.

The US has not provided evidence for the allegation, and Mr Blinken acknowledged that some people may question the claims. “But let me be clear. I am here today not to start a war but to prevent one,” he said.

The concerns were echoed by other Western leaders. Nato Secretary General Jens Stoltenberg warned of “a pretext for an armed attack”, while UK Foreign Secretary Liz Truss and Prime Minister Boris Johnson alleged that a false flag operation was being planned.

The spike in tensions on Thursday came after an exchange of fire between Ukrainian forces and Russia-backed rebels in the country’s east.

Such breaks in the years-long ceasefire are not uncommon. But each side blamed the other for Thursday’s violence.

Ukrainian officials accused Russia-backed separatists of striking a nursery in the town of Stanytsia Luhanska, smashing through a wall into a children’s music room. Three adults – but no children – were injured.

Russia-backed rebels, meanwhile, said Ukrainian forces had shelled a number of locations under rebel control and accused them of escalating the conflict.

There are also competing claims about the build-up of troops along Ukraine’s border.

Russia has said that, following the completion of military exercises, some of its troops are now returning to their bases. It has published video purporting to show tanks boarding trains as evidence.

But US and other Western officials said thousands more troops are arriving and insist there is no evidence of any significant withdrawal. They say that claim is backed up not only by intelligence, but by widely available satellite photographs.