'Incredibly serious mistake,' Biden says if Russia uses nuclear weapons in Ukraine

WASHINGTON

US President Joe Biden said it would be an "incredibly serious mistake" if Russia uses nuclear weapons in Ukraine amid allegations by Russia of Kyiv using a "dirty bomb."

"Russia would be making an incredibly serious mistake for the use of tactical nuclear weapons," Biden said at the White House after getting an updated coronavirus booster shot.

"I'm not guaranteeing you that it's a false flag operation yet. I don't know. But it would be a serious, serious mistake," he added.

The remarks were in response to a question about whether Russian allegations that Ukraine was preparing for a "dirty bomb" attack on its soil were the beginning of a false flag operation for Russia.

State Department spokesman Ned Price said Monday that Russia would face serious ramifications if it were to use a "dirty bomb" or nuclear weapon against Ukraine.

Price said should Russia use an improvised nuclear device against Ukraine, it "would certainly be another example of President (Vladimir) Putin's brutality."

"If he were to use a so-called 'dirty bomb,' there would be consequences for Russia, whether it uses a dirty bomb or a nuclear bomb," Price told reporters. He did not outline what types of responses the US is considering.

A dirty bomb combines conventional explosives with radioactive materials that spread across an area following detonation.

Russia has accused Ukraine of preparing to use such a device, a claim the West rejected as a potential cover for the Kremlin to use a dirty bomb.

The US, France and UK flatly rejected the suggestion Sunday, saying in a joint statement that each of their defense ministers "made clear" in separate telephone calls with Russian Defense Minister Sergey Shoygu "that we all reject Russia’s transparently false allegations that Ukraine is preparing to use a dirty bomb on its own territory."

"The world would see through any attempt to use this allegation as a pretext for escalation. We further reject any pretext for escalation by Russia," they said.