TEHRAN, Iran - Iraq's neighbours, including Iran and Syria, have agreed to join U.S. and British representatives at a regional conference here on the Iraqi security crisis, government officials said Wednesday.

Deputy Foreign Minister Labid Abawi told The Associated Press that Russia and France were studying the invitation, but "I don't see any sign they will refuse."

"Syria, Iran, Saudi Arabia, even the U.S and Britain have informed us they will participate," he said, although Tehran has said publicly it has made no decision. Abawi also said China had agreed to attend.

Abawi said the date would be set within two days. Iraqi state TV said the tentative date was March 10.

Prime Minister Nouri al-Maliki's adviser, Sami al-Askari, also said neighboring countries had agreed to come. Iran has publicly said it is studying the invitation.

"The conference will be important. It will prove that Iraq is politically capable of holding such a conference. It will send a message to the world," Abawi said.

Al-Askari said it would allow countries such as the U.S., Iran and Syria "to sit down together without paying a political price."

Washington's willingness to attend the conference marked a diplomatic turnabout after months of refusing dialogue with Tehran over calming the situation in Iraq.

Secretary of State Condoleezza Rice said Tuesday that the United States would join the meeting and that Washington supported the Iraqi government's invitation to Iran and Syria.

The Bush administration waited to embrace the idea until Iraq had made progress on a law governing national distribution of oil revenue.

"We did work with them on the precise timing of the announcement," said State Department spokesman Sean McCormack.

The failure of Iraq's parliament to pass the oil law has been an irritant in U.S.-Iraqi relations. The difficulty is symbolic of Iraq's regional, factional and political divisions, and passage is seen by the United States as a key marker of the government's will and ability to work across those divides.

"We work with them to encourage them to meet those benchmarks that they themselves have set," McCormack said. "This is something that they have been talking about for quite some time, and they thought the timing was right for them to hold the conference and so we encouraged them to move forward with it."

Ali Larijani, the head of Iran's Supreme National Security Council, said earlier that Iraqi Foreign Minister Hoshyar Zebari contacted Iranian Foreign Minister Manouchehr Mottaki to discuss the conference. "We are reviewing the proposal," Larijani said, quoted by the state TV Web site.

"We support solving problems of Iraq by all means and we will attend the conference if it is expedient," Larijani said. "We believe Iraq's security is related to all its neighboring countries, and they have to help settle the situation."

Larijani suggested the U.S. presence was not a problem for Iran. Asked by reporters if Iran was running a risk by attending the conference alongside the Americans, he replied, "One should not commit suicide because one is afraid of death" -- meaning Iran should not hurt itself just to avoid possible negative results.

Iranian hard-line President Mahmoud Ahmadinejad said on a visit to Sudan that supporting the "legal government of Iraq, its sovereignty and national unity ... are important elements for solving problems" in that country.

The Iranian state IRNA news agency quoted Ahmadinejad as saying that "Americans should amend their policy" in Iraq because the current one is "wrong." A Tehran state radio commentary also said the U.S. should change its Iraq policy if Washington expects the conference to produce a "rational conclusion."

Many Iranians feel resentful about the last major diplomatic dialogue with the United States -- when officials from both sides met before the 2001 U.S. invasion of Afghanistan to topple the Taliban, whom Tehran also opposed. Iran backed the invasion -- only to see President Bush name the country part of the "axis of evil" later.

The U.S. severed diplomatic relations with Iran in 1979 when Iranian militants occupied the U.S. Embassy in Tehran and held its staff hostage. Washington continues to have diplomatic relations with Syria, including a charge d'affaires at its embassy in Damascus.

The last time the U.S. and Iran had diplomatic contact was in late 2004 at a meeting of 20 nations in the Egyptian resort of Sharm el-Sheik to discuss Iraq's future. Then-Secretary of State Colin Powell and his Iranian counterpart, Kamal Kharrazi, did not hold formal talks, but Egypt sat the two officials next to one another at a dinner. Powell said the two mostly had "polite dinner conversation."

Larijani did not say what level delegate Iran would send if it chose to attend the conference. Rice said Tuesday the gathering would be at a sub-ministerial level, which would be followed by a full ministerial meeting, possibly in early April.

Syria will be represented by Ahmed Arnous, an aide to the foreign minister, a Syrian Foreign Ministry official said, speaking on condition of anonymity because the plans had not yet been formally announced.

Syria believes the U.S. participation in the conference was "a partial step ... in the right direction for comprehensive dialogue with Syria on all issues of the Middle East," the state SANA news agency quoted the Foreign Ministry official as saying.

Iraq's Ahmad Chalabi, an influential Shiite, said the conference was "long overdue" and expressed hope it would help "in building international support" for the Iraqi government.

"The Iraqi people have been waiting for such an international show of support for our struggle against terrorism and to rebuild our country," Chalabi said. "We will never accept Iraq becoming a battleground for other countries, nor will we accept Iraq becoming as base for destabilizing our neighbours."

Iran has said in past months it is willing to meet with the United States to discuss how to calm the violence in Iraq. But tensions have increased dramatically between the two countries recently.

Bush has stepped up accusations that Iran is backing anti-U.S. Shiite militants in Iraq, a number of Iranians in Iraq have been seized by U.S. forces, and the American military presence in the Gulf has been heightened.

At the same time, Washington has led a push for stronger sanctions against Tehran over its nuclear program. The United States accuses Iran of seeking to build nuclear weapons, which Tehran denies. The United Nations has demanded Iran suspend uranium enrichment before any negotiations over its nuclear program can be held, a condition Tehran has rejected.