BAGHDAD — American troops could face trial before Iraqi courts for major crimes committed off base and when not on missions, under a draft security pact hammered out in months of tortuous negotiations, Iraqi officials familiar with the accord said Wednesday.

The draft also calls for U.S. troops to leave Iraqi cities by the end of June and withdraw from the country entirely by Dec. 31, 2011, unless the Baghdad government asks some of them to stay for training or security support, the officials said.

It would also give the Iraqis a greater role in U.S. military operations and full control of the Green Zone, the 3Z\x-square mile area of central Baghdad that includes the U.S. Embassy and major Iraqi government offices.

One senior Iraqi official said Baghdad may demand even more concessions before the draft is submitted to parliament for a final decision. The two sides are working against a deadline of year's end when the U.N. mandate authorizing the U.S.-led mission expires.

The Iraqi officials, familiar with details of the draft, spoke on condition of anonymity because they were not supposed to release the information.

In Washington, the State Department confirmed a draft had been finalized but refused to discuss any details.

"There is a text that people are looking at," spokesman Sean McCormack told reporters. "Nothing is done until everything is done. Everything isn't done. The Iraqis are still talking among themselves. We are still talking to the Iraqis."

U.S. officials declined to discuss details of the draft but characterized it as the administration's final offer, saying no more concessions would be considered.