WATCH: White House press secretary Jen Psaki holds briefing as Russia puts nuclear deterrent on high alert

The White House says it sees “no reason to change” U.S. nuclear alert levels despite Russian President Vladimir Putin putting his nuclear forces on high alert amid fierce fighting with Ukraine.

Watch Psaki’s remarks in the player above.

Speaking at the White House briefing Monday, press secretary Jen Psaki said the administration is “assessing President Putin’s directive, and at this time, we soon see no reason to change our own alert levels.”

Psaki underscored that the White House believes that “a nuclear war cannot be won and must never be fought.”

“So we have not had seen reason to change our alert levels, and we see significant danger in escalatory rhetoric,” she said.

READ MORE: Putin put Russia’s nuclear forces on alert. What does that mean for the risk of nuclear war?

On Sunday, Putin dramatically escalated East-West tensions by ordering Russian nuclear forces put on high alert, while Ukraine’s embattled leader agreed to talks with Moscow as Putin’s troops and tanks drove deeper into the country, closing in around the capital amid fierce resistance.

Reports have surfaced that Russia is using “cluster bombs” in civilian areas of Ukraine, a type of munition that is banned by some 100 nations through an international treaty.

Psaki said she as no confirmation of the reports’ veracity, but added, if it is true, “it would potentially be a war crime.”

Asked also about Canadian Prime Minister Justin Trudeau’s move to unilaterally ban Russian crude oil imports and whether the U.S. might follow suit, Psaki reiterated, “all options are on the table.”

“You have seen us take a number of actions over the last several days that play that out, but I don’t have anything to predict at this point other than to reiterate that we have really worked to take steps in lockstep with the Europeans and a number of our NATO partners,” she said.