WATCH: Biden administration threatens Russia with a 'range of consequences' if nuclear weapons deployed

Fox News White House Correspondent Jacqui Heinrich asked President Joe Biden's National Security Adviser Jake Sullivan if the US would actively enter the war if Russian President Vladimir Putin used nuclear weapons in Ukraine.

"So I have said before that we have had the opportunity to communicate directly to Russia a range of consequences for the use of nuclear weapons and the kinds of actions the United States would take," Sullivan said. "I have also said before that we are not going to telegraph these things publicly."



As CNN reports, Putin said in a speech last week that "those who try to blackmail us with nuclear weapons should know that the prevailing winds can turn in their direction."

Heinrich followed up by asking if the US would "unprepared for a serious response if he [Putin] were to take that kind of action tomorrow" and if America needed to move more firepower into the region.

"We feel that we have in place right now the capacity to effectively deter and respond to any contingency and to make good on what President Biden emphatically reinforced today that we will defend every inch of NATO territory the United States has put in place the pieces for that," Biden's National Security Adviser said.

Sullivan added, "And if you look at what our NATO allies have done, in terms of searching their own capabilities to Eastern flank allies, upping their own defense expenditures, we are at a level, a state of readiness, to take on any contingency, and we're doing the act of coordination and scenario planning to be prepared for whatever comes our way."

Heinrich also asked about efforts to protect energy supply infrastructure after Nord Stream's I and II were recently sabotaged. 

Sullivan said the US was increasing surveillance and stepping up efforts to ensure protection.