By David Alexander
RAMSTEIN AIR BASE, Germany Feb 9 (Reuters) - The top U.S. military officer said on Saturday he was confident enough U.S. troops will remain in Afghanistan after 2014 to accomplish the three-part mission agreed to by allies at last year's NATO summit in Chicago.
Army General Martin Dempsey, chairman of the U.S. Joint Chiefs of Staff, said he did not know whether President Barack Obama would announce the size of the post-2014 U.S. force for Afghanistan during his upcoming State of the Union address.
But he said an announcement on the management of forces in 2013 "has to come fairly soon, simply because we're two months in(to)" the year. Officials have said a decision on the size of the post-2014 U.S. force would be made before any announcement of the speed of the 2013 drawdown.
Afghan forces are expected to take over the lead role for security in Afghanistan this spring. The international force plans to hand over full responsibility for security to the Afghans by the end of 2014, with most international combat forces being withdrawn.
Dempsey spoke to reporters while en route to Afghanistan for a change of command ceremony for the International Security Assistance Force. Marine Corps General John Allen will hand over command of the international coalition to Marine Corps General Joseph Dunford, expected to be the force's last commander.
Dempsey played down a suggestion by some White House officials that the United States might consider a "zero option" and leave no troops behind in Afghanistan. Dempsey said no one had suggested that to him, "and I would never recommend zero."
White House officials told reporters last month ahead of a visit by Afghan President Hamid Karzai that the possibility of leaving no troops behind after 2014 was an option.
"The military at this point is confident that the number will match the mission," Dempsey said. "Let me put it this way: I will not at any point ask 10,000 troops to do 20,000 troops' work."
At a NATO heads of state summit in Chicago last year, the leaders agreed that the post-2014 mission in Afghanistan would focus on counter-terror operations against al Qaeda, training and assisting Afghan forces and supporting other U.S. government diplomatic and development operations.
Dempsey said the only circumstance under which a zero option was likely to come into play was if the two sides failed to negotiate a bilateral security agreement, as happened in Iraq.
"This is why the bilateral security agreement is so important, because if we get this agreement in place soon, then it takes away all of the anxieties related to our enduring presence there," he said.
He noted that Karzai and Obama had agreed they wanted to complete a bilateral security agreement this year, if possible by the spring.
Dempsey said he thought the chances of reaching a security agreement that would provide immunity and other protections for U.S. forces were better in Afghanistan than in Iraq, where the United States failed to reach a deal.
"Using the lessons of Iraq we started this process sooner," he said, adding that it gave them more time to deal with internal domestic political issues.
He also noted that Afghanistan's economy was considerably weaker than Iraq's, which led Afghans to recognize they would need international support for the long-term, an issue that did not confront oil-rich Iraq. (Reporting by David Alexander; Editng by Vicki Allen)