Ukraine could face the worst-case scenario of a Russian invasion as soon as next week, and Europe faced one of its most perilous security situations since the early 20th century, British foreign minister Liz Truss said on Saturday.

“That worst-case scenario could happen as early as next week. The reality is that Russia does want to turn the clock back,” Truss told a security conference in Munich.

“In the last week alone, we’ve seen a doubling of disinformation, and we’ve seen false flag operations in the Donbass region. I’m afraid that Russia has shown that they are not serious about diplomacy,” she added.