US says taking Putin's 'irresponsible' nuclear threats 'very seriously'

WASHINGTON

The US is taking Russian President Vladimir Putin's "irresponsible" threats to use nuclear weapons "very seriously," the White House said Wednesday.

National Security Council spokesman John Kirby said that if the Russian leader should use doomsday weapons "there will be severe consequences," without laying out specific actions the US would take.

"Not only will he be that much more a pariah on the world stage, but there will have to be severe consequences from the international community," he said during an interview with ABC News.

Putin announced earlier Wednesday a mass mobilization in Russia of 300,000 reservists to support his flagging war effort in Ukraine, issuing a dire warning ahead of planned referenda in parts of Ukraine denounced by the West as a "sham" effort to annex additional Ukrainian territory.

"When the territorial integrity of our country is threatened, we will certainly use all the means at our disposal to protect Russia and our people. This is not a bluff," he said.

The move comes one day after the announcement of referenda in the Ukrainian regions of Donetsk, Luhansk, Kherson and parts of Zaporizhzhia. Putin and his regional proxies are seeking to use the polls to claim the territories as part of Russia.

Kirby said the actions are a reflection of Russia's battlefield setbacks as Ukraine's military mounts additional advances after routing the Kremlin's forces from the northeastern region of Kharkiv.

"Because he can't legitimately take some of these areas, he's trying to have some sort of political legitimacy of it so he can claim it's Russian territory. It is not. It won't be even as a result of the sham referendums," he said, referring to Putin. "That is Ukrainian territory doesn't matter what sham referenda they put in place or wouldn't vote they hold it still Ukrainian territory."

Speaking directly about the troop mobilization ordered by the Russian president, Kirby said the action is "definitely a sign he's struggling."

"We know he has suffered tens of thousands of casualties. He has terrible morale, unit cohesion on the battlefield, command and control has still not been solved. He's got desertion problems, and he's forcing the wounded back into the fight. So clearly, manpower is a problem for him," he said. "He feels like he is on his back foot."