Cooper, People magazine’s 2011 “Sexiest Man Alive,” sat down with Biden at the White House earlier this year.

He also spoke at a January press conference on mental health at the Center for American Progress in downtown Washington with former Rep. Patrick Kennedy (D-R.I.) and Sen. Debbie StabenowDebbie StabenowTrump's pick to lead Medicare won't say if she supports negotiating prices with drug companies Overnight Finance: Fed chief tries to stay above partisan fray | Bill would eliminate consumer agency | Trump signs repeal of SEC rule on foreign payments Lawmakers urge Trump to raise trade issues with Abe MORE (D-Mich.).

UPDATE (2:30 p.m.): Cooper told a crowd at the conference Monday afternoon, "I think that all of us are touched in a real meaningful way with this illness. And I think it is up to all of us to help. I want to help, I want to do something about it. I want to be part of the solution," before introducing Biden.

The vice president quipped, "I'm Joe BidenJoe BidenTop union offers backing for Ellison in DNC race John Kerry to teach at Yale on global issues Ellison needles Perez for 'unverifiable' claim of DNC support MORE, and I'm a friend of Bradley Cooper."

During his closing remarks, Biden told a story about staying at the same hotel as the "Hangover" star during a recent trip to Brazil. Joking that the entertainer had "caused me a great deal of pain recently," Biden said he had to disappoint his 12-year-old granddaughter by meeting with the president of Brazil rather than summoning Cooper to his suite.

"My standing with my granddaughter has plummeted," Biden cracked.

Justin Sink contributed.