Afghan delegates walk on the street on the second day of the Loya Jirga, or the consultative council in Kabul, Afghanistan, Friday, Nov. 22, 2013. Representatives from different groups gather in separate rooms and discuss until meeting again in the council. President Hamid Karzai urged tribal elders Thursday to approve a security pact with Washington that could keep thousands of U.S. troops in Afghanistan until 2024, but he added a wrinkle that he prefers his successor sign the document after elections next April. Afghan delegates discuss on the second day of the Loya Jirga, or the consultative council in Kabul, Afghanistan, Friday, Nov. 22, 2013. Afghan delegates listen to a speech from their committee chairman on the second day the Loya Jirga, or the consultative council in Kabul, Afghanistan, Friday, Nov. 22, 2013. Afghan delegates listen to a speech from their committee chairman on the second day of the Loya Jirga, or the consultative council in Kabul, Afghanistan, Friday, Nov. 22, 2013. Afghan delegates discuss on the second of the Loya Jirga, or the consultative council in Kabul, Afghanistan, Friday, Nov. 22, 2013. KABUL, Afghanistan (AP) - Afghanistan's president on Friday rebuffed American demands that he sign a security pact allowing U.S. forces to stay in the country for another decade, while the U.S. defense secretary warned that planning for a post-2014 military presence may be jeopardized if the deal isn't finalized by the end of the year. The stakes are high as Afghan tribal elders and other regional leaders met behind closed doors for a second day to debate the draft agreement seen as necessary to enable thousands of American soldiers to stay beyond a 2014 deadline primarily to train and mentor government security forces who are still struggling to face a resilient Taliban insurgency on their own. Karzai stunned the U.S. when he urged delegates on Thursday's opening day of the consultative council known as the Loya Jirga to approve the security pact but said he will leave it to his successor to sign it after the April 5 elections. His spokesman Aimal Faizi stuck to that stance on Friday despite U.S. pleas, saying "there is no deadline for us except what the president said in his speech." The Obama administration has said it will pull all its forces out of Afghanistan without a security deal, as it did when Iraq failed to sign a similar agreement. U.S. Secretary of State John Kerry called Karzai on Friday and warned that "further delay is not practical, nor is it tenable," State Department spokeswoman Jen Psaki said. "Failure to conclude (the deal)... would be seen as a signal to the world that Afghanistan is not committed to a partnership with its supporters and that it is willing to jeopardize all of the financial and practical help that has been offered," Psaki said. The longest and costliest war in U.S. history has proven deeply unpopular at home and among its allies, who also have said they will not commit any troops after 2014 unless the security deal is signed. The exit of all foreign forces would jeopardize the more than $8 billion that has been pledged annually to fund Afghan security forces and help with the country's development. Underscoring that point, U.S. Defense Secretary Chuck Hagel said Friday he can't recommend that President Barack Obama continue planning for a post-2014 force in Afghanistan unless Afghan leaders promptly sign the security agreement. Hagel said that without an agreement the U.S. will have no clear understanding of what the Afghan people want, what an acceptable role for U.S. forces will be or how to carry out that mission. He was speaking to reporters before the start of a security forum in Halifax, Nova Scotia. According to a senior U.S. defense official, Hagel spoke by phone with Marine Gen. Joseph Dunford, the top U.S. and coalition commander in Afghanistan, to receive an update on the Loya Jirga and ongoing discussions with the Afghan government on the bilateral security agreement. The official said Dunford told Hagel that Washington has sent a strong message to the Loya Jirga that the agreement must be approved now and signed without delay if Afghans want the U.S. and its allies to remain after 2014. The official was not authorized to discuss the private conversation publicly, so spoke on condition of anonymity. Kerry and Karzai agreed earlier this week to the language of the agreement, which would remain in force until the end of 2024 and beyond, unless terminated by mutual agreement or by either party with two years' written notice. The draft agreement gives the U.S. legal jurisdiction over troops and Defense Department civilians who may get in trouble, despite deep divisions in Afghanistan over whether the Americans should have immunity. It also addresses the contentious issue of night raids, saying "U.S. forces can only enter Afghan homes in extraordinary circumstances when the life or limb of Americans is at stake." The 2,500 delegates broke into small groups for closed-door meetings on whether to endorse the deal and will give their decision to Karzai on Sunday. The assembly is widely expected to approve the agreement, and Karzai's remarks could be seen as last-minute move to force the gathering to ask him to sign the long-delayed accord - thus shifting the responsibility for the deal away from him to the elders. Afghan experts in the U.S. also suggested that Karzai might be trying to pressure the U.S. into making more concessions. U.S. officials have not yet disclosed how many troops they want to keep in Afghanistan after 2014, but they have said the number of U.S. and NATO troops could be between 8,000 and 12,000. Associated Press writers Deb Riechmann in Washington and Lolita C. Baldor in Halifax, Nova Scotia, contributed to this report.