In his first interview since dropping out of the presidential primary campaign, Senator Bernie Sanders (D-VT) beamed into Stephen Colbert’s house on The Late Show. And the host’s big question was all about the “presumptive nominee” Joe Biden.

Asked if he’s spoken to the former vice president since making his decision to exit the race, Sanders said yes before quickly pivoting to what separates the two men as opposed to the many things that unite them.

“It’s no great secret that Joe Biden’s politics are different than mine,” he said. “But I have known Joe since I came to the Senate in 2006, worked with him when he was vice president in the Obama administration.” As he did in his address to supporters earlier in the day, Sanders called Biden a “decent human being” and added, “I hope to be able to work with Joe to move him in a more progressive direction.”

Calling Biden a “good politician,” Sanders said that Biden “understands that in order to defeat the president, that in order to defeat Trump, he’s going to need to bring new people into his political world” and “start moving in a different direction than he has in the past.”

With all of that in mind, Colbert asked Sanders directly, “Is that a full-throated endorsement of Joe Biden?” The host began to smile as Sanders evaded the question.

“We’re going to be talking to Joe and we are talking to his team of advisers,” Sanders said before repeating his promise to do “everything that I can to make sure that Donald Trump is not reelected.”

“I will do everything I can,” Sanders said, “but I will say that we’re talking to Joe and talking to his team about how we can work together.”