President Barack Obama on a surprise visit to Afghanistan on Friday told US troops "you will succeed in your mission," and stressed they were breaking the momentum of the Taliban.
"You're achieving your objectives, you will succeed in your mission," Obama told more than 3,000 exuberant soldiers gathered at Bagram Air Base.
"We said we were going to break the Taliban's momentum. That's what you're doing," he said after touching down at the air base outside Kabul.
But Obama, on his second trip as president to the war-torn country, warned "there are going to be difficult days ahead" in the fight against insurgents, and appeared to choke up as he described a visit to a base hospital where he pinned Purple Hearts on wounded soldiers.
"I don't need to tell you this is a tough fight," the commander in chief said. "I just came from the medical unit and saw our wounded warriors."
"I just talked to the platoon that lost six of their buddies in a senseless act of violence.
"It's a tough business," he said. "Progress comes slow." But he stressed to the troops, most from the 101st Airborne Division currently headquartered at the base, that "today we can be proud that there are fewer areas under Taliban control, and more Afghans have a chance to build a more hopeful future."
Obama, who has tripled US troop numbers in Afghanistan, was spending a mere three hours in the country. He met with war commander General David Petraeus and spoke by telephone with President Hamid Karzai -- after technical problems with a video link.
Obama's trip comes as his administration faces new friction with Karzai over embarrassing assessments of the Afghan leader in leaked diplomatic cables.
The administration is meanwhile working on a review of its war strategy to be completed before the president leaves for holidays in late December.
Obama assured troops that support for them was rock solid, despite misgivings among Americans about the war and its mission.
"Even though it is a hallmark of American democracy that we have our arguments back home... I can say without hesitation, there's no division, no hesitation on one thing: that is the uniform support of men and women serving in the armed services."