SARAJEVO, Bosnia-Herzegovina (AP) _ He was skeptical at first. But one look at Sarajevo's ruins convinced a California congressman that American soldiers are needed to keep Bosnia's peace.

Republican Rep. Ron Packard, leading a congressional delegation to the former Yugoslavia, wanted to see if it was safe for U.S. troops. He had opposed President Clinton's decision to send 20,000 Americans with the NATO peace-enforcing mission.

After meeting with Bosnian President Alija Izetbegovic and touring the war-ravaged capital Monday, Packard changed his mind.

``Only once before in my life have I seen devastation like I have seen here. That was in Berlin not too long after the last big war,'' the 64-year-old politician said. ``We want peace to work. If the American troops will help to bring that about, then we will be very supportive of the American troops being here.''

In other developments Monday:

_Officials worked behind the scenes to obtain the release of two French pilots, after Bosnian Serbs missed France's deadline to disclose the missing men's whereabouts. ``There are very serious negotiations taking place as we speak,'' Packard said.

White House Press Secretary Mike McCurry seemed optimistic that the pilots would be freed soon.

``There's been some activity in Belgrade. We are very hopeful the two French pilots will be released,'' he said Monday. ``They should be.''

_Serb supporters of the peace agreement took to the streets of Sarajevo to urge fellow Serbs there to end opposition that threatens to wreck the accord.

The congressional delegation followed its meeting with the Bosnian president with a 1 1/2-hour discussion late Monday in Belgrade with Serbian President Slobodan Milosevic. Packard emerged saying he was worried about peace, given Milosevic's vision of postwar Bosnia.

``From other presidents ... it was the sense that there would be an equal balance of power of all factions and therefore no interest in creating a warlike situation, because no one could win it,'' he said. ``We did not hear that tonight'' with Milosevic.

As the 15-member delegation gathered information on the safety _ and wisdom _ of sending U.S. troops, the Senate prepared for a debate Wednesday on whether to back Clinton's plan. The Senate will vote first, and then the House of Representatives.

Regardless of whether Congress approves, American soldiers will be part of the 60,000-strong NATO force to be deployed after Thursday, when Balkan leaders sign an accord in Paris to end 3 1/2 years of war.

A few U.S. Marines have gone to Sarajevo, but most American troops will be based around Tuzla in northwestern Bosnia. Brig. Gen. Sead Delic, commander of Bosnian troops around Tuzla, said his army will do its utmost to ensure the Americans' safety.

So it looks as if Clinton will have Packard's vote. But Packard added a caveat: If peace cannot be implemented, he said, ``then we are wasting our time. We would be wasting the effort of our troops.''

Packard's concerns were addressed Monday by the chief of staff for the NATO forces, who said his troops would use as much force as the job requires.

``Our rules of engagement ... are robust,'' U.S. Army Lt. Gen. William Carter told reporters in Zagreb, Croatia.

Carter also said the transfer of command from the United Nations to the NATO-led force will take place in Sarajevo on Dec. 19.

As the U.S. delegation toured Sarajevo, residents _ many of them Serbs _ demonstrated for peace in a government-held neighborhood across the river from the rebel Serb-held suburb of Grbavica.

Chanting ``Bosnia, Bosnia,'' demonstrators urged rebel Serbs to stop opposing a reunited Sarajevo.

``I beg our friends and neighbors from the other side to stay in their homes so that we can live together,'' Mile Plakalovic, a Serb from the Serb-held part of the city, told the crowd.

Many Serbs in Sarajevo have protested the peace agreement, which hands over their neighborhoods to the control of a Muslim-Croat federation.

Bosnian Serbs plan to hold a referendum Tuesday on whether to accept the peace agreement.

A Muslim woman mused on the irony of the demonstration.

``They were killing us and torturing us for four years, and now we are begging them to stay and live with us again,'' Selma Kovac said. ``Yet, when I think twice about it, it's OK. Someone always has to be first in offering the hand of reconciliation.''

A senior U.N. official said Monday that Serb leaders had threatened to destroy utility lines in Serb-held districts before the Bosnian government moves in.

U.N. officials said they plan to protect the utilities _ with force if necessary.

In Paris, preparations for the peace treaty signing were under way despite a continuing dispute between France and Bosnian Serbs over the fate of two French pilots shot down Aug. 30 over Serb territory.

France gave Bosnian Serbs until midnight Sunday to provide information about the missing pilots. The deadline expired with no word.

Karsten Voigt, a member of NATO's parliament, told independent Studio B-92 TV on Monday that Yugoslav officials gave him the impression the pilots were healthy.

``We are doing everything in our power to resolve the matter'' of the French pilots, said Serbian president Milosevic, who has great leverage with the Bosnian Serbs. ``We hope the outcome will be favorable.''

Packard refused to give details of the negotiations that he said were under way.