(AP Photo/Jacquelyn Martin, File)

President Obama said in a television interview broadcast Friday morning that former secretary of state Hillary Rodham Clinton would be "very effective" if she decides to run for president in 2016.

"I don't know what she's going to decide to do, but I know that if she were to run for president, I think she'd be very effective at that," Obama said in an interview with ABC's "Live with Kelly and Michael."

Obama described a close relationship with his former 2008 rival.

"Hillary and I -- we're buddies. I think because we ran in the longest primary in history and our staffs I think were doing battle politically, the perception was that this was always kind of a marriage of convenience when she came in as secretary of state. I always admired her," Obama said.

The president added that the two have "become really, really good friends."

Obama said he's been "blessed" to have people around him like Clinton and Vice President Biden who are "great, hardworking, effective people." Biden, like Clinton, is a potential 2016 candidate for president.

Obama and Clinton secretly lunched at the White House on Thursday. A White House official revealed the lunch only after a People Magazine tweet revealed that Clinton was on the property.

In the author's note in her upcoming memoir, Clinton writes that she formed an "unexpected partnership and friendship" with Obama after their heated 2008 Democratic primary campaign.