BAGHDAD - Iraq's political leaders have given the government permission to negotiate with the United States for a possible deal to keep American troops in Iraq to train security forces beyond this year.

But Foreign Minister Hoshyar Zebari says a final agreement is still far from settled, and Baghdad could insist the US military leave by the end of 2011 as required under a 2008 security agreement.

The small step forward on the politically charged issue came after a five-hour debate.

Earlier Tuesday, US Joint Chiefs chairman Adm. Mike Mullen left Iraq after urging the government to quickly ask for the troops to stay - or face their imminent departure.

Iraq is torn between its shaky security and war-weary public in weighing whether US forces should leave by December 31.