Joe Biden says Russia will be making an "incredibly serious mistake" if they use a nuclear weapon in Ukraine.
Joe Biden has sent a warning to Russia about nuclear weapons
The US President sent a renewed warning to Russian leader Vladimir Putin amid fears that his country is looking for an opportunity to unleash such a weapon on war-torn Ukraine.
Biden admits that he is still uncertain if Russia is trying to put together a "false flag operation" in which they would detonate a dirty bomb and blame it on the Ukrainians but warned of the implication if nuclear weapons are used during the conflict.
The president told reporters: "Let me just say: Russia would be making an incredibly serious mistake for it to use a tactical nuclear weapon.
"I'm not guaranteeing you that it's a false flag operation yet, don't know, but it would be a serious, serious mistake."
Russian military officials had accused Ukraine of planning to use a dirty bomb on their own soil but the claims have been rubbished by the US.
Karine Jean-Pierre, the White House press secretary, told reporters: "Russia is pushing transparently false allegations.
"In the past, we've seen Russia use allegations as a pretext to escalate. And as the president said, we don't know if that is the case here."
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