"I will not rule out that we may encounter each other," she said.

"This is not a meeting about the United States and Iran, this is a meeting about Iraq and about what Iraq's neighbors and interested parties can do to help stabilise the situation in Iraq," she said.

Earlier Iran announced that it will attend a key conference on Iraq's security in Egypt alongside arch-enemy the United States this week, ending weeks of uncertainty over its involvement.

Officials in Tehran and Baghdad said Iraq's Prime Minister Nuri al-Maliki spoke to Iranian President Mahmoud Ahmadinejad on the telephone to ask Tehran to take part in the conference and Ahmadinejad agreed.

"The Islamic Republic of Iran confirmed that it would attend the two conferences in Sharm el-Sheikh to assist Iraq at the level of foreign ministers," Maliki's office said in a statement.

"Ahmadinejad, taking into account Iran's support of the popularly-elected government of Iraq, said that Iran will take part at the level of foreign minister," an official from Ahmadinejad's office told AFP..

The decision for Foreign Minister Manouchehr Mottaki to represent Iran at the conference in the Egyptian Red Sea resort came after a flurry of diplomatic activity aimed at persuading Tehran to take part.

Mottaki's participation raises the possibility he could hold rare bilateral contacts with US Secretary of State Condoleezza Rice although Tehran has refused to discuss this issue until its participation was confirmed.

US President George W. Bush has said that Rice, who is also set to attend the conference, "could" hold talks with Mottaki at the Red Sea resort should Iran decide to participate.

Tehran had shown a reluctance to sign up for the May 3-4 conference in Sharm el-Sheikh, citing unhappiness with the decision to include world powers such as the United States alongside Iraq's neighbours.

Iraqi officials have been seeking to persuade Tehran to take part, and Iraqi Foreign Minister Hoshyar Zebari held talks last week in Tehran with Mottaki.

Tehran's attendance also appeared to be complicated by the continued detention by Washington in Iraq of five Iranian officials it arrested in January on accusations of seeking to stir trouble there.

Iran's top national security official Ali Larijani arrived in Baghdad on Sunday afternoon for a three-day visit to discuss the conference and other issues on a previously unannounced mission, state television said,

"The visit of Mr Larijani is in the framework of bilateral relations. He will probably talk about security questions and the international conference," foreign ministry spokesman Mohammad Ali Hosseini told reporters.

A visit by Iraq's Deputy Prime Minister Barham Saleh to Tehran later on Sunday was cancelled after Larijani decided to go to Iraq himself, state media reported.

Zebari's visit failed to win a clear pledge from Iran to attend the conference, but there had been mounting calls from influential voices inside Iran for Tehran to participate.

Former foreign minister Kamal Kharazi, who is now a member of the strategic foreign policy council that advises the Islamic republic's supreme leader, said on Friday that Iran should attend the conference for the sake of Iraq.