Russia's Putin has broken international law, Britain says

Russian President Vladimir Putin's recognition of breakaway regions of eastern Ukraine is a breach of international law, British Prime Minister Boris Johnson said on Monday.

While Johnson was speaking, Putin signed a decree recognising the independence of the regions of Luhansk and Donetsk regions, upping the ante in a crisis the West fears could unleash a major war.

"I gather just as I came into this press conference that Vladimir Putin has effectively announced that Russia is recognising the breakaway republics of Donetsk and Lugansk. This is plainly in breach of international law. It's a ... flagrant violation of the sovereignty and integrity of Ukraine," Johnson told a press conference.

"It is a repudiation of the Minsk process and the Minsk agreements, and I think it's a very ill omen and a very dark sign."

After Putin had signed the decree, British foreign minister Liz Truss said the move violated the U.N. Charter and signalled an end to the Minsk process - a set of agreements designed to end a separatist war by Russian speakers in eastern Ukraine.

"We will not allow Russia's violation of its international commitments to go unpunished," she said in a statement on Twitter.

Putin recognises Ukraine rebel regions as independent

Johnson said he would talk with Ukrainian President Volodymyr Zelenskiy on Monday and would offer Britain's support.

When asked whether it was now time to impose sanctions on Russia, Johnson said he would have to wait and see what happened in eastern Ukraine.

"What I have said before about the package of sanctions is that they will be triggered with the first toecap of a Russian incursion or Russian invasion. But plainly what has happened is extremely bad news," he said.

"It is becoming clear that we're going to need to start applying as much pressure as we possibly can because it is hard to see how this situation improves."