President Barack Obama hosts President Hamid Karzai at the White House on Friday at a meeting designed to thrash out the scope, and ultimately the size, of the US commitment to Afghanistan after 2014.
The leaders, whose relationship is strained by a grueling war that has stretched America's military, finances and public patience, will focus on Afghanistan's uncertain future capacity to meet its own security needs.
Obama is scheduled to hold two hours of discussions with Karzai in the Oval Office and Cabinet Room, followed by a lunch, before the two men brave the cameras for a short White House press conference.
They meet at a fateful moment, as Obama deliberates on the shape of a planned NATO-led training and anti-terror mission meant to support the Afghan army and ensure Al-Qaeda cannot return after NATO combat troops leave in 2014.
Afghan President Hamid Karzai attends a military ceremony at the Pentagon in Washington DC on January 10, 2013. The US sought to assure Karzai that it would remain committed to his country even as US officials weigh a major withdrawal of American forces.
Karzai backs a residual US presence but it depends on a yet-to-be concluded security agreement to govern issues like legal immunity for American soldiers and transferring detainees to Afghan custody.
The Obama administration failed to conclude a similar pact for post-war Iraq, prompting Obama to bring every US soldier home.
Karzai is shadowed by Afghan fears that his country could be abandoned again by the international community -- as it was after the end of the Soviet occupation in 1989.
The power vacuum led to the rise of the Taliban, and a safe haven for Al-Qaeda to plot the September 11 attacks, which drew the United States into an Afghan war in 2001.
Graphic showing the US troop deployment history in Afghanistan since 2001. A key decision on how many troops will remain after 2014 could be made at Friday's talks between President Barack Obama and Afghan leader Hamid Karzai in Washington.
Top US officials sought to ease those fears on Thursday, and both sides took pains not to publicly air differences over the quality of Afghan governance, corruption and the price civilians have paid in US military action.
Relations have also been strained this year by a string of attacks by Afghan soldiers on supposed NATO comrades.
"After a long and difficult past, we finally are, I believe, at the last chapter of establishing a sovereign Afghanistan that can govern and secure itself for the future," US Defense Secretary Leon Panetta told Karzai.
"We've come a long way towards a shared goal of establishing a nation that you and we can be proud of, one that never again becomes a safe haven for terrorism."
Afghan President Hamid Karzai (L) speaks during a meeting with Defense Secretary Leon Panetta at the Pentagon on January 10, 2013. Panetta told his "distinguished visitor" that more than 10 years of war had paved the way for Afghanistan to stand on its own.
Panetta later told reporters he and Karzai, who met alone for about an hour, made "some very good progress."
Karzai was hopeful that Washington and Kabul would be able to work out a security agreement.
"Afghanistan will, with the help that you provide, be able to provide security to its people and to protect its borders; so Afghanistan would not ever again be threatened by terrorists from across our borders," he said.
Later, Karzai was guest of honor at a dinner for 15 people at the State Department hosted by Hillary Clinton, which she said was meant to repay "some of the hospitality I've enjoyed over the years."
The White House talks come as the freshly re-elected Obama charts out plans to pull most of the 68,000 US troops out of Afghanistan. The United States and allies have already agreed to withdraw combat troops by the end of 2014 but questions remain on a US training and security role after that.
US President Barack Obama speaks at of the White House in Washington DC on January 10, 2013. Obama's crucial meeting on Friday with Afghan President Hamid Karzai is expected to focus on how many US troops will remain in Afghanistan after the 2014 drawdown.
The White House has reportedly ordered the Pentagon to come up with plans for a smaller Afghan presence than the generals expected, perhaps numbering 3,000, 6,000 or 9,000 US troops.
Obama's domestic political opponents, however, charge that if the US presence lacks sufficient capacity, the president risks squandering gains wrought in a war which has killed more than 3,000 coalition troops.
US officials caution that the Obama-Karzai talks will not produce a deal on a specific number of troops but could impact that figure by narrowing down the exact purpose of those who will remain behind.
Ben Rhodes, a deputy national security adviser, even said Tuesday that Obama would not rule out any ideas -- including the possibility of leaving zero American boots on the ground.
US military officers later privately acknowledged those comments were primarily designed as a tactic in negotiations with Kabul -- and they might also have been part of internal wrangling over troop levels with the Pentagon.