Barack Obama arrived unannounced in Afghanistan on Sunday, his first visit to the war zone that could define his presidency since his election as U.S. commander-in-chief.
Air Force One landed in darkness at Bagram airfield north of the Afghan capital, and Obama was whisked by helicopter to Hamid Karzai's palace in Kabul, where he was greeted by the Afghan president and a band playing the U.S. national anthem.
U.S. officials said Obama would press Karzai to crack down on corruption and battle drug trafficking. He will also hear a briefing from the commander of U.S. and NATO forces in Afghanistan, Army General Stanley McChrystal, and deliver a speech to U.S. troops.
The president left Washington on Saturday night. White House spokesman Robert Gibbs, speaking before the trip, said Obama wanted to get an "on the ground update" about the war from McChrystal and Karl Eikenberry, the U.S. ambassador.
National security advisor General James Jones told reporters on Air Force One that Obama would tell Karzai "in this second term that there are certain things he has to do as the president of his country to battle the things that have not been paid attention to almost since day one."
In December Obama ordered the deployment of an extra 30,000 U.S. troops to Afghanistan and set a mid-2011 target to begin withdrawal. About a third have so far arrived, participating in a major offensive in the south of the country last month.
The Obama administration has had an uneasy relationship with Karzai throughout Obama's 14 months in office, reaching a nadir during a three-month Afghan election dispute last year.
Eikenberry wrote in a classified cable in November, later leaked, that Karzai was "not an adequate strategic partner."
The trip allows Obama to see any early results of his troop increase, show support for military personnel and counter critics who say his focus on passing healthcare legislation has diverted attention from foreign policy.
Since he took office, the 8-year-old war in Afghanistan has shifted from a second priority behind Iraq to the main effort of the U.S. military. Within the next few months, the number of U.S. troops in Afghanistan will have tripled under Obama's watch to 100,000, along with about 40,000 from NATO allies.
Obama's domestic victory on healthcare reform last week gives him political space to turn his attention to the Afghan war, which has mixed support from the American public amid rising casualties, costs, and corruption among Afghan leaders.
Obama traveled to Afghanistan during the 2008 U.S. presidential election campaign after being criticised by Republican challenger John McCain for failing to tour the war zone, but has not been back since his victory.
The White House official said weather and logistical reasons had thwarted previous attempts at a presidential visit since Obama took office in January 2009.
Much has changed during Obama's first year in office.
Top U.S. officials held two long reviews of the White House's war policy, both times electing to send tens of thousands of extra troops.
Karzai, who remained in power after a fraud-marred election, has launched a high profile effort to seek reconciliation with the Taliban, who have made a comeback more than eight years since their ousting by U.S.-backed Afghan militias.
U.S. Defense Secretary Robert Gates said last week the timing was still not right for reconciliation with senior Afghan Taliban leaders.
Obama speaks less often to Karzai than did his predecessor, former President George W. Bush, who launched the war in the aftermath of the Sept. 11, 2001, attacks on the United States.