"In order to define the terms of reference of this committee and its responsibilities there will be meetings at the level of experts" from the three countries, Hassan Kazemi Qomi was reported by the ISNA news agency as saying.

He added that "the meeting will take place next week."

"During the second session of talks between the three countries, agreement was reached to establish a tripartite security committee," Kazemi Qomi added.

The US embassy press office in Baghdad said that officials had been working towards holding such a meeting, but that they were not aware whether any date had yet been set.

On July 24 the delegations of Iran and the United States, led by Kazemi Qomi and US ambassador to Baghdad Ryan Crocker respectively, were unable to agree during a landmark second meeting on ways to restore security to Iraq.

But Iraq said the two arch-foes did agree to participate in a tripartite security committee aimed at curbing militia activity, battling Al-Qaeda and securing border areas, but without reference to extremist Shiite militias that Washington says are backed by Tehran.

The US military in Iraq regularly accuses groups linked to Iran of training extremists in the war-ravaged country and supplying them with explosives capable of penetrating American armoured vehicles.

Iran denies supporting insurgent groups in Iraq.

US State Department spokesman Sean McCormack on July 25 confirmed that Washington was examining the idea of establishing a subcommittee "which would actually be lower level, technically oriented officials."