The meeting was firstly revealed by Iraqi Foreign Minister Hoshyar Zebari, who told a press conference following the Iraqi security meeting that the American-Iranian meeting took place at expert level, not at foreign minister level.

He, however, noted that "I don't know what happened during their meeting but I believe it is positive."

According to media reports, the meeting took place between U.S. Ambassador to Iraq Ryan Crocker and Iranian deputy foreign minister Abbas Araghchi, with the US State Department's Iraq coordinator, David Satterfield, presented.

It was very limited, very short and it was on Iraq, said the Ambassador Crocker after the meeting.

The meeting was held following a Thursday afternoon meeting between U.S. Secretary of State Condoleezza Rice and Syrian Foreign Minister Walid al-Muallem on the sideline of the ministerial meeting of the International Compact with Iraq (ICI).

Muallem was accompanied by Egyptian Foreign Minister Ahmed Abul Gheit into a meeting room for bilateral talks, where Rice was waiting, sources concerned told Xinhua, adding the two sides held face-to-face talks for 30 minutes.

Relations between Washington and Damascus have been strained since 2003 as Syria, also an ally of Iran, strongly objected the U.S. invasion of Iraq and blamed the U.S.-led occupation for the turbulences in the country ever after.

The United States, on the contrary, has been accusing Syria of supporting terror organizations and doing little to stop weapons and militants from infiltrating into Iraq and destabilize situation there.

Muallem told Xinhua sources after the meeting with Rice that the talks was "constructive" and the atmosphere was good.

The talks dealt with both how to help Iraq regain security and stability, including the issue of infiltrated militants on the Syrian-Iraqi border alleged by the United States, and bilateral relations between Washington and Damascus, he said.

During lunch time on Thursday, Rice and Iranian Foreign Minister Manouchehr Mottaki, both attended the two-day Iraq conference, exchanged brief greetings by saying hello to each other, though they didn't meet to hold foreign ministerial level talks as the world had expected.

The process needs more work as there is a lot of suspicion and mistrust between Iran and the United States, Zebari said, adding it is in Iraq's interest to see a reduction of this tension.

Talking about the U.S.-Iranian expert-level meeting, Egyptian Foreign Minister Ahmed Aboul Gheit expressed a welcome and termed it as "the beginning hopefully of a process".

Rice, who said that if she had had the chance she would also have met her Iranian counterpart Mottaki, noted that U.S. officials did have an opportunity to exchange views with Iranian officials about the substance of the Iraqi security meeting aimed at helping Iraq be more secure.

However, no miracle has happened. On contrary, Mottaki on Friday harshly criticized the U.S.-led occupation of Iraq, which "has worsened the situation in the war-torn country".

Speaking at a press conference, Mottaki said Iraq has gone through very painful and difficult period where women and children were killed every day.

The U.S. has accused Tehran of arming Shiite militias and inciting anti-US attacks in Iraq, while Iran denies any involvement in the violence.

The United States must accept the responsibility arising from the occupation of Iraq and should not fingerpoint or put the blame on others, Mottaki denounced.

He, meanwhile, called for a timetable for U.S. withdrawal and release of five Iranian civil servants seized by the United States in the northern Iraqi Kurdistan in January this year.