Obama: Al-Qaida Would Use Nuke if It Could

Obama said securing loose nuclear arms is "a central part of the process, but probably the most urgent one and the one we are most concerned with in the short term."

After his remarks, Obama met with Pakistani Prime Minister Yusuf Raza Gilani. The White House said Obama praised Pakistan for its quick reaction to an attack by Islamic militants against a U.S. consulate in northwestern Pakistan last week. Obama also reiterated that the U.S. and Pakistan are facing a common enemy.

Pakistan has a troubled history with the United States, and anti-American sentiment runs high among ordinary Pakistanis. U.S. leaders go out of their way to assure Pakistan that the United States will not walk away from the improving relationship with Pakistan, and Congress has committed billions in new aid to the country.

Reagrding the purpose of the summit, the White House said Galani assured Obama that Pakistan takes nuclear security seriously and has appropriate safeguards in place.

Obama wrapped up his Sunday schedule by meeting with acting Nigerian President Goodluck Jonathan before returning to the White House.