Biden: Russia will 'pay a severe price' if chemical weapons are used

President Biden on Friday warned that Russia would pay a severe price if it launched a chemical weapons attack during its invasion of Ukraine.

"I'm not going to speak about the intelligence ... but Russia would pay a severe price if they use chemical weapons," Biden said when asked if the U.S. would have a military response if Russian President Vladimir Putin launched such an attack.

He didn't comment further or mention if that response would include U.S. military involvement.

Biden administration officials have raised alarms about the threat that Russia will escalate its war on Ukraine with chemical weapons and have raised the prospect that Russia is laying the foundation for such an attack.

White House press secretary Jen Psaki on Thursday said she wouldn't get into hypotheticals when asked what the U.S. might do in response to this kind of escalation.

"What we're saying right now is they have the capacity and capability," she said. "I'm also not going to get into intelligence. But the president's intention of sending U.S. military into Ukraine against Russia has not changed."

She avoided laying out a red line when asked if the use of chemical or biological weapons would change Biden's position in terms of direct U.S. involvement in the war.

"We are directly involved. We are providing a billion dollars in security assistance. We are the largest provider of that," she said.

"With the U.S. military going and engaging in Ukraine and fighting a war against Russia? We don't have any intention to do that," she added when asked specifically about involving U.S. troops.