ABIDJAN -- Embattled Ivory Coast President Laurent Gbagbo was set Friday to break his silence on a French-brokered peace deal as the UN Human Rights chief said parties to the country's civil war may face international trial for executions and other crimes.

Governments and organizations worldwide have become increasingly concerned over security in Abidjan as it becomes clear that the peace deal signed in France last month is not being implemented.

the United States has dispatched a military team to review security at its embassy in Ivory Coast amid mounting unrest in the West African country, the State Department said.

The 10-strong "emergency survey and assessment team," sent by the U.S. European command from its base in Germany, arrived in the commercial capital Abidjan on Wednesday and will remain there for seven to 10 days, said Tara Rigler, a department spokeswoman.

"The team will assist embassy officials with reviewing embassy security requirements and security planning," she said.

Meanwhile a detachment of some 150 French troops was due to leave a base in southeastern France late Thursday to boost forces in the troubled West African state, military officials in Paris said.

Colonel Didier Castres, commander of France's 21st marine and artillery infantry regiment, said his forces were being dispatched for four months.

They are part of reinforcements of some 450 troops, who are to take the size of the French force in the country to some 3,000.

Their main job will be to protect French nationals in Ivory Coast, which slid towards civil war since an army rebellion last September.

As security fears here increased, the United Nations and world bank decided to withdraw non-essential staff from the war-torn Ivory coast Thursday as the UN Human Rights chief said parties to the conflict may face international trial for executions and other crimes.

Dozens of UN staff were due to leave Ivory Coast after the world body declared it to be in phase 4 on a five-phase risk scale -- of which the last phase requires the total withdrawal of staff.

This means that the staff of some 30 of the 110 international bodies operating in the world's leading cocoa producer will be pulled out, and that no UN official can visit the country without the authorization of Secretary general Kofi Annan. The World Bank said in a communique said it was following suit as it was under "the umbrella of the United Nations" and added that it would "temporarily relocate" non-essential staff in neighboring countries." The bank said "essential staff, including the director of operations, will remain in Abidjan to ensure that work goes on and dialogue with Ivorian authorities is maintained."

Meanwhile, embattled President Gbagbo was preparing to break his silence on the peace deal by addressing the nation at 8:00 P.M. (2000 GMT) Friday.

"I am working on my speech, I will make the address at eight," he told some cocoa and coffee planters who met him Thursday.

Rebels insist the deal gives them the defense and interior ministries in a unity government that clips Gbagbo's powers. This ignited national anger and anti-French riots causing France to advise its nationals to leave the ex-colony.

The UN decision will have an impact on the Abidjan-Based African Development Bank (AFDB) which had decided to relocate immediately if the world body declared Phase 4.

The AFDB, based in Abidjan since its creation in 1963, has grown into a 33 billion dollar multinational bank. Its presence is a source of pride for Ivory Coast, buttressing its erstwhile reputation as a stable regional economic powerhouse with world-class infrastructure.

UN High Commissioner for Human Rights Sergio Vieira de Mello meanwhile said those responsible for sweeping abuses and executions during the war were "liable" to be tried by the International Court of Justice (ICJ). Speaking to reporters in Paris after meeting with French President Jacques Chirac, De Mello said: "The (UN) Security Council can submit to the court what is happening in Ivory Coast."

The Ivorian conflict has been complicated by the discovery of two mass graves thought to contain up to 200 bodies and hate attacks on West African immigrants following Abidjan's charge that neighboring Burkina Faso was behind the unrest.

In a related development, the UN on Wednesday published a damning report which said the so-called "death squads" accused of killing, kidnapping and torturing people, of being backed by the state. The Ivorian government has denied any link with the so-called death squads.(AFP)