The meeting, to be attended also by an Iraqi delegation, has been confirmed by officials in all three camps.

As with a first round of talks on May 28 -- their first since Washington broke off relations with Tehran in 1980 -- the US will be represented by its Ambassador to Baghdad, Ryan Crocker, while Tehran's envoy Hassan Kazemi Qomi will head the Iranian delegation.

"After my meeting with the Iraqi Prime Minister Nuri al-Maliki, tomorrow's meeting was confirmed," Qomi was quoted as saying on the website of Iran's state-run television.

"An Iraqi delegation will be in our meeting with the American delegation, during which ways to seek stability and security in Iraq will be discussed," he added.

Spokesman for the US mission in Baghdad Philip Reeker confirmed the meeting, which was first announced late Sunday by Iraqi Foreign Minister Hoshyar Zebari.

Washington broke off relations with Tehran in 1980 after Islamic revolutionaries seized the US embassy in Tehran and held its diplomats hostage for 444 days.

A first ice-breaking meeting between the two sides on May 28 did not achieve any major breakthrough and was strictly limited to the security situation in Iraq.

Both sides stuck to their familiar positions, with Tehran calling for US troops to be pulled out and Washington accusing Iran of stoking the insurgency that is bedevilling Iraq.

Reeker said the meeting on Tuesday would also be strictly "about Iraq."

The two countries remain at loggerheads over a range of issues including Iran's nuclear programme, which the United States claims is aimed at producing nuclear weapons, an accusation fiercely denied by Tehran.

US forces have frequently accused Iran of arming and training Iraqi militias, allegations that are also denied by Tehran.

Relations have been chilled further by the detention in Iraq by US forces of at least five Iranian officials who Tehran insists are diplomats, but Washington says are members of Iran's elite Revolutionary Guard.

Strains have also come from the detention by Tehran of three US-Iranians accused of espionage and harming national security by being linked to alleged US efforts to topple Iran's clerical authorities.