Senior US and Iranian officials met at a crucial international conference on Iraq on Friday but mediators failed to arrange a meeting at a higher level between the two old foes.
The meeting in the Egyptian resort of Sharm el-Sheikh was another step away from the Bush administration's longstanding policy of avoiding contact with governments which actively oppose its policies in the Middle East.
US Secretary of State Condoleezza Rice met Syrian Foreign Minister Walid al-Moualem in Sharm el-Sheikh on Thursday -- the first contact at this level in more than two years.
Rice, whose country broke off diplomatic relations with Iran in 1980 when Iranian students held 52 US citizens hostage, said that if she had had the chance she would also have met Iranian Foreign Minister Manouchehr Mottaki.
"The opportunity simply didn't arise for the foreign minister of Iran and me to meet... I would have taken that opportunity," she told a news conference.
"But our officials did ... have an opportunity to exchange views about the substance of this meeting, which is how to help Iraq be more secure," she added.
The US ambassador to Iraq, Ryan Crocker, played down the meeting, saying he spent just three minutes discussing Iraq with Iranian Deputy Foreign Minister Abbas Araghchi.
The Iraqi government, which depends on US military support but also has close ties with Shi'ite Iran, had pressed for a Rice-Mottaki meeting but the Iranians were cool to the idea.
Iraqi Foreign Minister Hoshiyar Zebari welcomed the lower level US-Iran meeting as a "a positive sign".
"There is a lot of suspicion. There is a lot of mistrust. But it is in my country's interest really to see a reduction of this tension," he told a news conference.
The United States has accused Shi'ite Muslim Iran of promoting violence in Iraq, which has been pushed to the brink of sectarian civil war by fighting between Shi'ites and Sunnis. Tehran dismisses the charge.
Iran blames United States
On Thursday evening, Mottaki left dinner in Sharm el-Sheikh before Rice arrived to sit at the same table but Rice denied that the Iranian had snubbed her by not agreeing to meet.
"Well you can ask him why he didn't make an effort. Look, I'm not given to chasing anyone," she said.
Asked why he did not meet Rice, Mottaki told a news conference: "There was no time, no appointment and no plans."
"A meeting between foreign ministers has certain requirements (such as) political will and it also has to be clear on what basis such a meeting would be held," he added.
As well as the tensions over Iraq, Washington suspects Tehran's nuclear program is aimed at producing nuclear weapons. Iran says it is purely for generating electricity.