Starmer says Britain won't be deterred by 'irresponsible' nuclear rhetoric from Russia

British Prime Minister Keir Starmer said on Tuesday he would not be deterred from supporting Ukraine by "irresponsible" Russian rhetoric, after Russian President Vladimir Putin lowered the threshold for a nuclear strike.

"There's irresponsible rhetoric coming from Russia, and that is not going to deter our support for Ukraine," he told reporters at the G20 summit in Brazil.

Putin's new nuclear doctrine lowers the threshold under which Russia might use atomic weapons to include responding to attacks that threaten its territorial integrity.

The move comes as Ukraine used US ATACMS missiles to strike Russian territory on Tuesday, taking advantage of newly granted permission from the outgoing Biden administration on the war's 1,000th day.

Addressing that milestone in the conflict, Starmer said that Putin was the "author of his own exile" as he did not attend the G20 leaders' summit for the third year in a row.

"I say again (to Putin): end the war, get out of Ukraine," Starmer said.