WASHINGTON — The American Embassy in Baghdad warned Iraq’s president not to take up an offer to meet with the Iranian and Syrian leaders in Tehran, two administration officials said.

Nonetheless, aides to President Talabani announced yesterday that he would take up the offer from Iran’s President Ahmadinejad, whom Mr. Talabani accused in October of meddling in his country’s affairs.

One administration official said yesterday that the warning from the embassy was not a “direct order.”

“This was more like us saying that the meeting was a bad idea because of the timing,” the official, who requested anonymity, said. “This is a Middle Eastern thing. Everybody pretends they are friends, but they still hate each other.”

The meeting, scheduled for Saturday, is significant because it could lay the groundwork for a regional Iraq security conference, an idea already endorsed by many congressional Democrats, including Senator Levin, the Michigan lawmaker who will take over the Senate Armed Services Committee in January. It also is likely that a bipartisan panel studying Iraq policy options — co-chaired by a former secretary of state, James Baker — also will recommend renewed contacts with the Iranians and Syrians.

But others in the Bush administration have been wary of reaching out. Syria and Iran have cooperated in supporting Hezbollah in Lebanon, and in June, the two countries, which are effectively backing opposing sides in Iraq’s civil war, signed a mutual defense and intelligence-sharing pact.

Yesterday, the Associated Press quoted an Iraqi member of parliament, Ali al-Adeeb, as saying the purpose of the Saturday meeting is to discuss ways to stabilize Iraq, which is reeling from a rash of kidnappings in Baghdad and the summary execution of day workers in Hilla.

“All three countries intend to hold a three-way summit among Iraq, Iran, and Syria to discuss the security situation and the repercussions for stability of the region,” Mr. Adeeb, who is a member of the same political party as Prime Minister al-Maliki, said.

In Washington, news of the summit prompted words of caution from the State Department’s deputy spokesman, Tom Casey. “I think the thing that has concerned us, and still does concern us, is the fact that while there have been positive statements from the Iranian government about wishing to a play a positive role in Iraq, those statements haven’t been backed up by actions,” he said. “And so very much what we’d like to see the Iranian government do is desist, first and foremost, from negative actions it’s taken in Iraq.”

Those negative actions include support for Iraq’s Shiite militias, which have been responsible for the torture and deaths of scores of Sunni Arabs in the last year.

The inclusion of Syria in the conference has also worried the State Department. Not only has Syria provided aid, arms, and funding to Sunni Arab terrorists in Iraq, but the Bush administration has also been trying to isolate Damascus in the last two years, in part because of Syria’s alleged role in the assassination of a former Lebanese prime minister, Rafik Hariri.

“I think, as we have always said with respect to the Syrians, you know, the problem is not what they say, the problem is what they do,” Mr. Casey said. “So what would be in our view the next step would be to have them move beyond those words and actually take some concrete steps in that direction.”

Syria’s foreign minister, Walid al-Moallem, met yesterday with Mr. Talabani in the first visit of a Syrian high official since the fall of Saddam Hussein.

Iraqi leaders have had regular contact with Iran since 2003. Mr. Talabani led a delegation in 2003 to Tehran to sign a series of agreements, including one dealing with counterterrorism cooperation.