BAGHDAD — Defense Secretary Leon Panetta told Iraq’s leaders Monday that they must decide soon whether to ask for U.S. troops to remain beyond the end of the year. But the U.S. does not intend to broker negotiations among Iraqi politicians that could ultimately lead to agreement for a continuing presence, senior American officials said.

Panetta’s visit stood in sharp contrast to past tours by high-ranking U.S. officials under the Bush administration or even by Vice President Joe Biden in trying to push Iraqi leaders to take action. The subdued trip comes eight months after Biden helped persuade Iraqi leaders to form a government after a lengthy stalemate that followed a too-close-to-call national election.

Yet even now, terms of the deal remain largely unfulfilled, including the formation of a strategic national council headed by secular prime minister finalist Ayad Allawi, as well as the naming of interior and defense ministers.

It is this failure that Iraqi officials warn could sabotage any chances for an agreement on U.S. troops staying. “”It will be much easier if a mutual understanding exists among the blocs about the shape of the (Iraqi) government,”” said Deputy Prime Minister Roj Nouri Shawis, a Kurd.

At this point, it still remains unclear whether Allawi and Prime Minister Nouri al-Maliki can make peace. Without rapprochement, al-Maliki does not have the political protection to win parliamentary approval for a security agreement that would allow a small number of American troops to remain in Iraq. Currently, al-Malaki relies on the political support of anti-U.S. Shiite cleric Muqtada al-Sadr to stay in office and al-Sadr wants all U.S. troops out at the end of the year.

Members of Allawi’s Iraqiya list, meanwhile, wonder openly why they should support an extended American military presence, when the deal to form a government that the U.S. helped broker last November has not been realized. They see al-Maliki serving as acting interior and defense minister and feel the U.S. government didn’t live up to its commitments.

“”If the Americans stay and do not take a position on anything, their presence will be useless,”” said Deputy Prime Minister Saleh Mutlaq from Iraqiya. “”They must change their policy.””

In separate meetings with al-Maliki and President Jalal Talabani, Panetta said, “”we need to know as soon as possible”” if American forces will be asked to remain and that “”message was clearly understood,”” according to Doug Wilson, assistant secretary of defense for public affairs.

The Obama administration, at least in public, has refused to become directly involved in urging Iraq to ask for some of the 46,000 U.S. troops still in Iraq to remain after December, even though senior American military officers have made clear they would likely look favorably on such a request.

But as the withdrawal deadline set during the Bush administration approaches, American officials are warning that as the planned pullout of personnel and equipment gains momentum, a point will be reached where it will be impractical to halt.

“”As you get deeper and deeper into the fall, it gets harder and harder”” to halt the pullout, Gen. Lloyd Austin, the commander of U.S. forces in Iraq, said Monday. “”When you get into the October, November time-frame, you are really taking things apart that are really difficult to put back together.””