WASHINGTON, D.C. -- President Barack Obama, who's been a Chicago Bulls supporter much longer than he's been the commander in chief, seamlessly transitioned from politician to trash-talking fan Monday when surrounded by the back-to-back champion Los Angeles Lakers.

"Derrick Rose may have your number," President Obama lightheartedly jabbed at Kobe Bryant as the team posed for a photograph after presenting the president with an autographed replica 2009-10 championship banner, like the one that hangs at Staples Center.

President Obama met with the Los Angeles Lakers in Washington, D.C. on Monday where they participated in community service at a Boys & Girls Club. Jewel Samad/AFP/Getty Images

Without skipping a beat, Bryant made a similar transition from gracious guest at the Boys & Girls Club of Greater Washington, where the Lakers participated in a series of community service projects, to a proud player protecting his spot at the top of the pecking order.

"I said, 'If he calls that number, I'll be sure to pick up after the fifth ring,'" Bryant quipped back -- referring, naturally, to the five championship rings he has.

It was just a bit of good-natured ribbing on a day when the Lakers and the president teamed up with NBA Cares to do a lot of good. The team prepared toiletry kits for the homeless and care packages for wounded veterans and their families.

They added a personal touch to the assortment of candy, gift cards and various other sundry goods by teaming up with the children to produce handwritten letters that were added to the packages.

"It was perfect," Bryant said. "It was different and it accomplished great things. Being around the kids, but then preparing all of the [care packages] and writing letters for our troops, you can't beat it."

Mariame Diallo, 15, was one of the approximately 100 children involved in the day's event. She said it was touching to write a letter to a stranger, hoping it will cheer them up.

"I felt as though they need to know that people care," Diallo said. "I wrote, 'Happy holidays. Blessings come with prayer, and we care, from the Boys & Girls Club.'"

Last season, the Lakers met President Obama at the White House with every player and coach wearing a suit and tie. This year, the players wore track suits and the coaches wore sports jackets and slacks, but no ties. The activity was more important than the attire.

"There's a long-standing tradition of welcoming championship sports teams to the White House, but here's the thing: These guys have been there so often and they were just there last year because they won the title, and Kobe and Derek [Fisher] have been there so many times now they can lead tours themselves, and the same is true for coach [Phil] Jackson, so I thought we'd change things up a little bit," President Obama said. "That's the beauty of service, anybody can do it. The Lakers have a proud tradition of performing community service in the L.A. community and I'm glad they took the time to help us during the holiday season here in Washington, D.C."

President Obama addressed a small crowd that included California Congresswoman Grace Napolitano for about five minutes and worked in another Bulls reference when he spoke about L.A.'s accomplishments.

"I want to congratulate coach Phil Jackson on earning his 11th NBA championship ring," President Obama said. "It was his fifth championship ring with the Lakers, which I should point out is still one behind the six he won with the Chicago Bulls."

As the president stood on stage with the team behind him, he heard a voice interject, "Not for long."

"Kobe said, 'Not for long,'" the president said with a laugh.

President Obama added that it has been "a long drought" for Chicago since Jackson last coached the Bulls to a championship in 1998, but took some pride in the fact that the Bulls beat the Lakers 88-84 on Friday in the first game of L.A.'s current six-game road trip.

"I have to say they witnessed in person on Friday that my Bulls are showing some signs of life," President Obama said.