BAGHDAD, Iraq, March 25 — With fewer than 100 days to go before Iraq resumes its sovereignty, American officials say they believe they have found a legal basis for American troops to continue their military control over the security situation in Iraq.
After months of concern about the legal status of the 110,000 American troops who are expected to remain here after the occupation formally ends on June 30, the officials say they believe an existing United Nations resolution approving the presence of a multinational force in Iraq, approved by the Security Council in October, gives American commanders the authority needed to maintain control after sovereignty is handed back.
Showing his confidence that the approach was grounded in international law, L. Paul Bremer III, the chief of the occupation authority, issued an executive order this week specifying that the newly formed Iraqi armed forces be placed under the operational control of the American commander, Lt. Gen. Ricardo S. Sanchez, who has been named to lead American and allied forces after the transfer of political authority to the Iraqis.
Mr. Bremer and other top American officials say they believe Security Council Resolution 1511, which conferred the mandate for the American-led alliance, can be used to provide legal justification for the American military command to operate until Dec. 31, 2005. That is when a timetable agreed on by Iraqi leaders envisages the final transition to an elected Iraqi government.
The plan, the American officials say, will require the Security Council to review the resolution before it expires in October. But the United States may also seek a new resolution, hoping to placate Spain's new prime minister, José Luis Rodríguez Zapatero, who has said that he will withdraw Spain's contingent unless the force is placed under clear United Nations control.
The Americans hope they will not be forced to rely on a legalistic argument. They plan to negotiate with the interim Iraqi government in place after June 30 for the kind of "status of forces" agreement the United States has in dozens of nations where its forces are deployed.
But if negotiations snag — many Iraqi political leaders are often hostile to the foreign military presence — the Americans believe that they will be able to fall back on the United Nations resolution.
That remains to be tested.
Some Iraqi politicians maintain that United Nations mandate was intended to lapse at the return of sovereignty. But American officials, citing a passage in the resolution saying that the mandate would expire "upon the completion of the political process," argue that it will not lapse until a permanent Iraqi government takes office.
European and United Nations diplomats said Thursday that American control would still have to be approved by the Iraqis taking office on June 30. That control, said a United Nations official, "is not likely to survive the transfer of sovereignty unless the successor government approves it."
There were also questions about the effects of extending the primacy of the American military.
The United Nations official said that while it would be a "practical reality" for American domination to continue despite Iraqi self-rule, "it has to be done in a way that's not offensive to Iraqis and the international community, which emphasizes Iraqi sovereignty rather than Iraqi impotence."
A European diplomat said that continued American military control "sends the wrong signal" and "gives an impression of continuing foreign occupation" in Iraq.
Nevertheless, in recent interviews, American officials and military commanders said they were confident that they had found a way to avert the possible political crisis that loomed after Iraqi leaders made it plain that no status-of-forces talks would occur before June 30.
American concern has focused primarily on Grand Ayatollah Ali al-Sistani, a Shiite cleric who has become a champion of the Shiite majority and of Iraqi nationalism and who has thrown a succession of political roadblocks in the path of the American plan for transition to Iraqi rule. He has rejected the interim constitution adopted by the Iraqi Governing Council, an advisory body handpicked by the Americans, and, some Iraqi politicians believe, could eventually try to derail the status-of-forces discussions.
One of the most influential members of the Governing Council who has close relations with the Americans offered support on Thursday for the American approach. The council member, Adnan Pachachi, a Sunni and a former Iraqi foreign minister, said it made sense to rely on the resolution as a fallback. He also said he supported Mr. Bremer's decision to put Iraq's military forces under American control.
Mr. Pachachi is favored to be the Sunni representative on the three-member presidency council that will head the interim government. In an interview at his Baghdad home, he said all Iraqis, including Shiite clerics restive under the occupation, recognized it was in Iraq's interest to have American troops remain to fight the intensifying terror campaign of insurgents loyal to the deposed Iraqi dictator, Saddam Hussein, and Islamic militants.
Mr. Pachachi said it had become common for Iraqis to say that it would be best if the country's security passed into Iraqi hands after June 30. But he suggested, with a colorful turn of phrase, that Shiite clerics and others who took this view were resorting to gesture politics without foundation in the harsh realities facing Iraq.
"Bearded and nonbearded gentleman have been saying, `The question of Iraqi security should be left to Iraqis,' " he said. "But if we Iraqis do not have the means to do this by ourselves, the withdrawal of American forces would be a disaster, for the beards as well as the nonbeards."
Top aides to Mr. Bremer have said in recent days that the American troops will act as the most important guarantor of American influence. In addition, they said, the $18.4 billion voted for Iraqi reconstruction last fall by the United States Congress — including more than $2 billion for the new Iraqi forces — will give the Americans a decisive voice.
The American determination to retain military control was clear from a document released by the occupation authority on Thursday summarizing Mr. Bremer's executive order on the Iraqi forces.
The order provided for the establishment of an Iraqi Defense Ministry to be headed by an as-yet unnamed civilian, which will oversee the new 40,000-soldier Iraqi Army the Americans expect to have trained by this fall. The Defense Ministry will also control the Iraqi civil defense force, which will also be 40,000-strong. Mr. Hussein's army, disbanded by Mr. Bremer last summer, had 715,000 men.
The document was unequivocal on the ultimate control of the Iraqi forces. "All trained elements of the Iraqi armed forces shall at all times be under the operational control of the commander of coalition forces for the purpose of conducting combined operations," it said.
The document also outlined plans for Mr. Bremer to appoint an Iraqi forces chief of staff and a national security adviser for three-year terms, and an inspector-general with a five-year term.
A senior American official said "it was expected" that the interim government would leave the appointees in their jobs at least until elections early next year produce a national assembly and a second-phase transitional government.
In practice, another senior official said, any Iraqi government would be unlikely to replace the appointees before the permanent government takes office in January 2006.
"The American commander would only have to say, `O.K., we're out of here,' and the Iraqis would back down," he said.
Another official said Iraqis could hardly claim that Iraq's sovereignty was compromised by having its troops under American command when nations like Britain and Poland had placed military contingents here under an American general. "There's no sovereignty issue for them," the official said.
Steven R. Weisman contributed reporting from Washington for this article.