Obama, the presumptive Democratic presidential nominee, flanked by his traveling companions, Sens. Charles Hagel, R-Neb., and Jack Reed, D-R.I., told a news conference in Amman, they have all been struck by "the promise of this moment."

Obama, D-Ill., traveled to Afghanistan and Iraq earlier this week to assess the military situation and burnish his foreign affairs credentials.

"If we responsibly end the war in Iraq, we can strengthen our military, step up our efforts to finish the fight against al-Qaida and the Taliban in Afghanistan and succeed in leaving Iraq to a sovereign government that can take responsibility for its own future," Obama said.

Obama said he still thinks U.S. troop strength in Iraq can safely be drawn down during the next 16 months, despite the reservations of tribal leaders in Anbar province and elsewhere. He said though violence and ethnic strife are down, he realizes the suspicions are still there and that U.S. troops are seen as "more honest" brokers in resolving those differences.

Obama arrived in Jordan Tuesday, where he is expected to discuss the Israeli-Palestinian conflict, Iraq and Iran with Jordanian leaders.