CNN
White House national security adviser Jake Sullivan speaks during an event at the Israeli Embassy in Washington, DC, marking the anniversary of October 7.
CNN  — 

A top US official indicated that the Biden administration was unaware of reported conversations between Russian President Vladimir Putin and former President Donald Trump since Trump left office – but suggested that such calls would “raise red flags.”

Veteran journalist Bob Woodward reported in a new book that there have been “maybe as many as seven” conversations between the two leaders since 2021, citing a Trump aide.

“I do not know if that’s true or not,” Biden national security adviser Jake Sullivan told reporters aboard Air Force One Thursday when asked about the calls.

“Obviously,” Sullivan added, “That would raise red flags if it were true.”

Asked by CNN whether the administration was trying to ascertain more details about those calls, the White House declined to provide specific information. But the comments from Sullivan were notable with fewer than three weeks until the presidential election, given how rarely he wades into political discourse.

Trump has denied having multiple calls with Putin, calling it “absolutely wrong” in an interview on Newsmax last week. Days later at the Chicago Economic Club, he declined to comment on whether the Putin calls had taken place, but said it would have been a “smart thing” if he had.

The Harris campaign has seized on the reporting as it seeks to cast Trump as a friend to authoritarian figures.

“We have examples of Donald Trump just constantly admiring dictators and autocrats, saying he wants to be a dictator on day one,” Vice President Kamala Harris told reporters last week.

She continued, “Let me tell you something: That’s a sign of weakness of character, that you would seek favor and flattery from dictators, and put their needs over the needs of the American people.”

Her running mate, Gov. Tim Walz of Minnesota, has also attacked Trump on the matter on the campaign trail, telling supporters, “I can guarantee you Kamala Harris and I do not have dictators on speed dial.”