The 50 groups making up the "loya jirga" gathering of about 2,500 chieftains, tribal elders and politicians gave unanimous backing to the pact at the end of four days of discussions under tight security in Kabul.
The assembly urged Karzai to sign by the end of the year the Bilateral Security Agreement (BSA) governing the presence of the troops after 2014, the date for most NATO combat forces to pull out. Karzai told the opening of the meeting on Thursday that the deal would not be signed until after April's presidential election -- sparking a strong response from Washington, which wants it sealed by the end of this year.
A closing statement agreed by delegates asked him to sign before the end of 2013. "Given the current situation, and Afghanistan's need... the contents of this agreement as a whole is endorsed by the members of this Loya Jirga," said the statement read by jirga deputy Fazul Karim Imaq. In his response, Karzai did not explicitly address when the deal would be signed, but he stressed that it would only proceed under certain conditions.
The pact must be approved by the Afghan parliament before it can go into effect.
These included US "cooperation" in Afghanistan's efforts to make peace with the Taliban, who have led the 12-year insurgency against Karzai's government and its foreign backers. Karzai also stipulated that there could be no more US military raids on Afghan homes, a sensitive topic that threatened to derail the deal last week.
"If the US goes into Afghan homes one more time, there will be no agreement, I repeat, if they go into our homes one more time, there will be no agreement," Karzai said.
The pact must be approved by the Afghan parliament before it can go into effect. But the question of when it would be signed has largely overshadowed discussions of its content in recent days. The US State Department warned that failure promptly to sign the pact -- which governs the conditions of any post-war American counter-terrorism and training mission in Afghanistan -- could jeopardise billions of dollars in vital aid to the war-torn country.
The White House has said it needs a swift decision to start planning the movement of US troops, and warned that President Barack Obama had not yet decided whether to keep any American forces in Afghanistan at all beyond 2014. Karzai's long-time ally and the jirga chairman, Sebghatullah Mojadidi, threatened to leave the country if the president refused to sign the pact.
Other delegates shouted: "Sign it, sign it." Supporters say the deal is vital for after 2014, when the bulk of NATO's 75,000 remaining troops will pull out. The Taliban insurgency this year has reached levels of violence not seen since 2010, according to the United Nations. Karzai told delegates that the BSA would allow up to 15,000 foreign troops to stay.