PORT-AU-PRINCE, Haiti — United Nations troops are coming back to Haiti, but after a decade of failed missions many in the traumatized country wonder whether the peacekeepers -- cobbled together from countries ranging from Argentina to Zimbabwe -- are up to the daunting task.

Although the official handover is Tuesday, only 42 of some 8,000 troops and police have arrived.

Brightly coloured flags of 30 participating countries dot empty barracks at the airport. Only samples of the blue UN headgear have arrived.

Floods that killed nearly 1,700 people last week and stranded thousands in remote villages have forced U.S. troops to stay past their June 1 departure date. Canada has some 450 troops in Haiti as part of the multinational peacekeeping force.

Unless they get new marching orders, the 1,900 U.S. troops will leave at the end of June, many to return to combat in Iraq.

Some Canadian, Chilean and French troops, from the 3,600-force that arrived in February when a rebellion ousted president Jean-Bertrand Aristide, will join the UN force for up to six months.

"We've done an excellent job in working with the multinational task force and we look forward to working with the other nations," said Canadian Capt. David Devenney.

The UN force, to include 6,700 troops and 1,622 civilian police, will be led by 1,200 Brazilian troops, the largest contingent the South American country has sent on a UN mission.

But Brazilian army Gen. Augusto Heleno Ribeiro Pereira recently warned Haitians not to expect miracles. Heleno, the commander of the UN force, arrived Tuesday. He is expected to be joined by 150 more troops Tuesday for the symbolic handover.

"Our first priority is helping the Haitian people," Heleno said Monday, donning a blue cap. "It will not be an easy mission but we are prepared to do the work it takes."

The UN mission will again try to keep a tentative peace in the divided country and again train an ill-equipped and understaffed police force, as well as work on development projects.

UN Secretary General Kofi Annan has asked for a long-term UN commitment to transform Haiti -- which has suffered more than 30 coups in 200 years -- into "a functioning democracy." But only a fraction of the $35 million US in requested aid has arrived.

Although Annan has urged countries to commit to Haiti, the mission is only for six-months now with no guarantees it will be extended.

"You can't just fix the problem and run," said Adama Guindo, a UN representative who will head the six-month mission to Haiti until a permanent leader is appointed. "I tend to believe that this time we are going to make a difference."

Whether the force will reach full strength is unclear. Brazil, Chile and Argentina have pledged up to 2,500 troops. Other countries, from strife-torn countries such as Nepal and Rwanda, have weighed in with sizable contributions of 750 troops each.

"I don't understand what they're coming to do yet," said Marie Andre, 31, from the southern village of Fond Verrettes, one of the worst affected towns in the floods. "If they're supposed to provide security, where are they?"

Some Haitians are hopeful that without Aristide the UN will be able to do more.

U.S. troops last intervened in Haiti in 1994 to restore Aristide after a 1991 coup. In 1995, they handed over to UN peacekeepers. That mission was supposed to last a year but continued until February 2001, unfolding as the Haitian government held disputed parliamentary and presidential elections which ultimately soured relations with the international community.

Foreign governments demanded a re-count of flawed 2000 legislative elections swept by Aristide's party. When Aristide refused, they froze tens of millions of aid dollars.