Sen. Mark Udall (D-Colo.) tweeted back and forth with Sen. John McCain Monday morning after the Arizona Republican praised him in an interview published Sunday.

Speaking with David S. Broder of The Washington Post, McCain had included Udall and his cousin Sen. Tom Udall (D-N.M.) in a list of the "next generation of stars" he hopes to work with.

McCain noted that the late Morris Udall — Mark's father and Tom's uncle, who represented Arizona in the House for 30 years — had been his political mentor.

Udall tweeted Monday that he appreciated the reference.

"@SenJohnMcCain thanks 4 calling me a rising Senate leader. Let's keep working together," he said, linking to the article.

McCain replied quickly.

"Thx, Mark," he said.

In the interview, McCain also said he hopes to mentor Sen. Lindsey Graham (R-S.C.) and Republican Senate candidates Kelly Ayotte (N.H.) and Carly Fiorina (Calif.).