The Obama administration mostly has repaired its relationship with Mr. Karzai, but mistrust remains on both sides.
The U.S. official, speaking on condition of anonymity to discuss sensitive diplomacy, said before the meeting that Mr. Obama and Mr. Karzai also were to discuss prospects for a political settlement or peace pact between Mr. Karzai’s government and the Taliban-led insurgency. The Taliban pulled out of U.S.-led talks in March, but separate talks among Afghan and other contacts continue, the U.S. official said.
The official said Mr. Obama believes political reconciliation is essential to the country’s future security.
The Taliban is urging nations fighting in Afghanistan to follow France’s lead and pull their international forces from the war this year.
“We call upon all the other NATO member countries to avoid working for the political interests of American officials and answer the call of your own people by immediately removing all your troops from Afghanistan,” the group said in a statement before the meeting.
The insurgent group cited declining public support for the war in the West and said political leaders should listen to their constituents and get out of Afghanistan.
The national security-focused NATO summit caps an extraordinary weekend of international summitry. Mr. Obama and the leaders of the world’s leading industrial nations convened at Camp David, the presidential retreat in Maryland, for two days of talks focused in large part on Europe’s economic crisis.
Joining Mr. Obama and many of the G-8 leaders in Chicago are the heads of NATO alliance nations and other countries with a stake in the Afghan war.
Prominent among those nations is Pakistan. Tensions between the U.S. and Pakistan have been running high following several incidents, including the U.S. raid in Pakistan that led to the death of Osama bin Laden and a U.S. airstrike that killed two dozen Pakistani soldiers.
Both countries have been seeking to restore normal relations. Pakistani President Asif Ali Zardari’s acceptance of an invitation to attend the NATO summit was seen as an indication that his country would reopen major roads used to supply NATO fighting forces in Afghanistan, a key U.S. demand.
White House officials said that while they believe an agreement on reopening the supply routes will be reached, they do not expect that to happen during the NATO meetings. The two nations are haggling over how much Pakistan will be paid to allow the heavy transport truck to pass through. A senior U.S. official said the two sides are far apart. The official spoke on condition of anonymity to discuss sensitive diplomacy.
Officials have indicated that Mr. Obama and Mr. Zardari will not hold a separate bilateral meeting until the matter is resolved. Although miffed, Mr. Zardari is expected to see Secretary of State Hillary Rodham Clinton and other U.S. officials in Chicago.
“I do hope that we will see a reopening of the transit routes in the very near future,” Mr. Rasmussen said. “These negotiations will continue, but I am hopeful that they will be concluded in a positive manner.”
AP writers Ben Feller and Desmond Butler contributed to this report.