Croatian President to Meet Clinton : Balkans: A key condition Franjo Tudjman set for allowing U.N. troops to remain may prove difficult to meet.

Croatian President Franjo Tudjman is expected to meet Thursday with President Clinton and later in the week with U.N. Secretary General Boutros Boutros-Ghali to work out details of a continued U.N. troop deployment in Croatia.

The high-profile U.S. visit is seen as a pay-back to Tudjman for reversing his decision to expel 12,000 U.N. peacekeepers in his country, thereby averting a new round of fighting between Croats and rebel Serbs.

But a key condition for Tudjman’s change of heart could make it extremely difficult for the United States and other members of the U.N. Security Council to come up with a revamped mission that will be acceptable to all sides, U.N. and diplomatic sources say.

Tudjman’s demand that U.N. troops control major Croatian border crossings with Serbia and Bosnia-Herzegovina would require a dramatically stepped-up U.N. posture and could increase chances of armed conflict involving U.N. troops, a senior U.N. military official in Zagreb said Tuesday.

“It ups the ante and significantly changes the U.N. mandate,” the U.N. Protection Force source said. “It is a much more combative position.”

The official said the U.N. military command in Zagreb is pressing U.N. negotiators in New York to clarify what a new border patrol would entail.

If the United Nations wants peacekeepers to control the border, the official said, the Security Council must give its force here the authority to stop, search and turn back Serbian soldiers, arms and supplies.

“If the (rebel Croatian Serbs) wanted to come in force, it would take an enormous amount to stop them,” the official said.

Some Western diplomats said the world body’s presence would probably involve monitoring, not controlling, crucial border checkpoints, because rebel Krajina Serbs in Croatia and their allies in Belgrade are unlikely to accept increased U.N. muscle along the disputed border.

But a U.S. official at the United Nations in New York said that the issue is “up for negotiation” and that officials are sensitive to Tudjman’s position.

The Croatian leader has already been criticized by political opponents for giving in to Western demands on the U.N. presence. A Croatian government news release lists U.N. control of Croatia’s borders as one of three items essential for an extended U.N. stay.

“Tudjman needs reassurances on both the substance” and the appearance of the U.N. deployment, said the U.S. official, explaining that Tudjman must be persuaded that armaments from Serbia will not reach rebel Serbs in Croatia and that any deal he strikes with the United Nations will look good to Croats.

The United Nations already monitors about 30 border points in Croatia with unarmed troops, according to the senior military official. But the troops do not get involved in preventing border crossings.

Even if the United Nations agrees to strengthen its border role, however, the augmented military presence will risk becoming nothing more than a symbolic display, the official said.

Serbs determined to cross into or out of Croatia could simply find an uncontrolled stretch of the porous, 600-mile border to shuttle fuel, ammunition and supplies, he said.

To seal the entire border--something no one has suggested--would require as many as 10,000 more U.N. troops, he said.

Troops would be better utilized along the cease-fire line between the Croatian government forces and the rebel Krajina Serbs, the official said. Flare-ups along the “separation zone” have increased in recent weeks.

Meantime, nine French peacekeepers died Tuesday when their truck plunged off a road on Mt. Igman near Sarajevo, the Bosnian capital. It was the largest loss of life for the United Nations in any single incident in three years of peacekeeping in the former Yugoslav federation. Their deaths brought the number of peacekeepers killed since 1992 to 148, including 94 in accidents.

Times staff writer Stanley Meisler at the United Nations contributed to this report.