Top White House economic advisor Gary Cohn pretended to have a bad connection to get off a call with President Donald Trump this month, a Democratic senator said Wednesday.

Sen. Tom Carper of Delaware told CNN that Cohn took the call from the president during a discussion with Democratic senators about tax reform. Carper said Cohn wanted to have a conversation on tax reform without Trump, who was traveling in Asia at the time.

CNN tweet

"About 30 minutes into the call, Gary gets up and takes a call on his cellphone, comes back into the room, and says, we have somebody calling in from Asia, and it was the president, which was nice. Nice of him to do that," Carper said, according to a transcript shared by a CNN reporter. "15 minutes later, the president is still talking. And I said to Gary, it was a room where we're all sitting around this big table, and I said, Gary why don't you do this, just take the phone from, you know, your cellphone back and just say, 'Mr. President, you're brilliant! But we're losing contact, and I think we're going to lose you now, so good-bye.'"

"And that's what he did, and he hung up," Carper said.

A CNN anchor then asked if Cohn faked a bad connection to get off the phone with Trump.

"Well, I wouldn't — I don't want to throw him under the bus, but yes," the senator responded.

The White House denied Carper's account.

"Senator Carper's claim is completely false. Gary Cohn took the phone off speaker and continued to speak with the president privately for several minutes before they concluded the call," said Raj Shah, White House principal deputy press secretary.

A source who was in the room told CNBC that Cohn did not fake a bad connection but said "the president was talking and talking and the novelty had worn off." Cohn "sensed" that senators were ready to get back to the meeting and left the room to finish the call, the source said.

Cohn, the White House chief economic advisor, is one of two officials leading the Trump administration's push for tax reform.

The former Goldman Sachs executive publicly criticized Trump in August over his response to violence at a white nationalist rally in Charlottesville, Virginia. Cohn reportedly drafted a resignation letter at the time.

— CNBC's Eamon Javers contributed to this report