The foreign ministers of Algeria, Bahrain and Tunisia were appointed last May to hold consultations on the situation in Iraq by the 22-member Arab League, whose Secretary General Amr Mussa was also attending the closed-door talks.
Zebari, who arrived in Tunis on Tuesday, was expected to review the security situation in Iraq one month after the handover of power by US-led occupying forces to the US appointed interim government of Prime Minister Iyad Allawi, an Arab diplomat told AFP.
A Security Council resolution last month provided for the establishment of an international force to provide protection for UN staff in Iraq.
International UN personnel quit Iraq in the wake of a massive bomb attack at the UN headquarters in Baghdad last August that claimed 22 lives including that of the top UN envoy to Iraq, Brazilian Sergio Vieira de Mello.
UN headquarters in Baghdad
was hit on 19 August 2003
The veteran Pakistani diplomat Ashraf Jehangir Qazi is to replace him.
Last week, Allawi called on other Arab countries to send troops to his country to help protect the UN mission when it resumes work.
Reluctant Arab League
At a meeting with Egyptian President Hosni Mubarak in Cairo, Allawi said: "We asked Egypt to make the necessary contacts with leaders of some Arab and Islamic countries to contribute forces to protect the UN mission."
Mussa had previously said that Arab soldiers could not go to Iraq until US-led occupation forces had left the country.
Speaking on condition of anonymity, the Arab diplomat said the troika was not authorised to make decisions but would hold simple consultations ahead of a meeting of the League's ministerial council in September.
At the Arab League summit in May, held in Tunis, Arab countries refused to send troops to Iraq under the supervision of the US-led occupation there. For its part Iraq did not want neighbouring Arab countries - Syria, Saudi Arabia, Jordan and Kuwait - to contribute to any eventual Arab contingent.
"We are negotiating with Poland and the United States concerning the number of our soldiers and the length of their stay - we can't stay very long."
Yevhen Marchuk, Ukrainian Defence Minister
On Wednesday, a spokesman for Mubarak's office said Egypt did not want to take part in an international protection force for a UN mission in Baghdad.
Ukraine will not allow its troops to remain part of the US-led force in Iraq for long and is negotiating with the US-led forces over their future in the country, Ukrainian Defence Minister Yevhen Marchuk said on Thursday.
"We are negotiating with Poland and the United States concerning the number of our soldiers and the length of their stay - we can't stay very long," Marchuk told journalists.
This former Soviet republic, which has sought closer ties with the United States, currently has a contingent of 1,650 troops serving as peacekeepers in the southern Iraqi sector overseen by Poland.
The defence ministry is preparing to rotate the contingent in September or October, Marchuk told journalists.
Despite offering its troops for the US-led war, Ukraine still has strained relations with Washington, which is concerned by Kiev's human rights record and alleged black market arms sales.