Afghans say deal agreed with U.S. for Obama to acknowledge war 'mistakes' KABUL (Reuters) - The Afghan government said on Tuesday it had reached a deal on the framework of a security pact with the United States after receiving assurances that President Barack Obama would issue a letter acknowledging U.S. mistakes made during the 12-year war. But despite the Afghan announcement, the Obama administration did not confirm that it had agreed to such a letter, which could draw criticism from Republicans and anger U.S. veterans of the war. And the State Department said some issues between the sides still had to be resolved before a final deal was reached with Afghanistan that would allow U.S. troops to stay there beyond 2014. Afghan President Hamid Karzai and U.S. Secretary of State John Kerry, in a phone call on Tuesday, overcame the main stumbling blocks to an agreement that will be put before the Loya Jirga, an assembly of Afghan tribal and political leaders due to meet in Kabul on Thursday, Karzai's spokesman said. Without an accord on the so-called Bilateral Security Agreement, the United States has warned that it could pull out all its troops at the end of next year and leave Afghan forces to fight alone against a resilient Taliban-led insurgency. Two years ago, Washington ended its military mission in Iraq with a similar "zero option" outcome that lead to the withdrawal of all of its troops after the failure of talks with Baghdad. Aimal Faizi, Karzai's spokesman, said the two sides agreed on crucial provisions giving U.S. troops immunity from Afghan law and allowing them to enter Afghan homes in exceptional circumstances, something the Afghan president had resisted. "Both sides agreed that Obama send a letter ... assuring the president and the people of Afghanistan that the right to enter into Afghan homes by U.S. forces and the extraordinary circumstances will not be misused," Faizi told reporters in Kabul. Asked whether a letter of that nature would be issued, White House spokesman Jay Carney told reporters: "I don't have any specifics on any language of a letter that hasn't been written." A senior State Department official said Kerry told Karzai that "we will consider his request for reassurances including the option of a letter from the administration stating our position." Karzai had long objected to a security pact that gives U.S. forces the authority to raid Afghan homes and granting immunity from Afghan prosecution, but Washington has said such provisions are crucial for its troops to remain in the country beyond 2014 when most foreign troops are due to leave. Additional reporting by Dylan Welch, Matt Spetalnick, Lesley Wrougton, Mirwais Harooni, Patricia Zengerle and Adrian Croft; Writing by Dylan Welch; Editing by Maria Golovnina, Ralph Boulton and Philip Barbara