KIGALI, Rwanda -- Within hours of arriving in Kigali, a contingent of 85 U.S. troops had the Rwandan capital's war-battered airport ready to launch round-the-clock operations to ease the plight of millions of refugees.


U.S. Defense Secretary William Perry visited the city, where he was welcomed by victors of the three-month civil war, although the new leaders said international aid had come too late for countless thousands.


"Now what the international community has to help us to do is get our people back. You cannot rule a country without a population or you would be like a government of the Sahara Desert," said Prime Minister Faustin Twagiramungu.


French Prime Minister Edouard Balladur said Sunday that, to avoid destabilization, French troops might stay on in a safe zone for refugees in southwest Rwanda beyond the expiry of their UN mandate on Aug. 22. "We will not withdraw unless we have the feeling that the zone is safe and that it will remain safe after our departure," he told French television in the Zaire border town of Goma after touring the refugee disaster area by helicopter.


Western governments, which did very little during the bloodbath in which 500,000 Tutsis and opposition Hutus were butchered by Hutu militias, have stepped in to help hordes of refugees to make the journey home. Aid workers estimate a fraction of Kigali's original 350,000 residents have headed back but are desperately worried a new epidemic could ravage the returning population.


About 20,000 refugees who fled victorious forces of the Rwanda Patriotic Front into eastern Zaire have died in a cholera epidemic this month. Aid staff warn diseases such as dysentery and meningitis could kill many more.


Western troops deploying in Kigali over the next few days aim to set up field hospitals and mobile ambulance units along the road from Zaire to screen out and treat cholera sufferers. The U.S. soldiers who arrived at Kigali airport Sunday swiftly got to work establishing power and readying the runway to operate round-the-clock for aid flights.


About 150 out of a contingent of 440 Canadian troops have also arrived, and starting Tuesday 550 to 600 British soldiers will begin deploying for the humanitarian mission.


Perry said the opening of Kigali airport would allow the doubling of relief supplies going into Goma, where more than 1 million refugees still languish.