U.N. Officials Urge More Bosnia Troops : Balkans: Military, civilian leaders plead for a doubling of force. Cease-fire in Sarajevo at risk, they say.

The civilian and military heads of the U.N. peacekeeping mission for the Balkans appealed Thursday for a near doubling of the troops deployed to Bosnia-Herzegovina, warning that a precarious cease-fire in Sarajevo could collapse without swift reinforcement.

As Sarajevo endured scattered mortar and machine-gun fire in violation of a U.N.-brokered truce that is 3 weeks old, Yasushi Akashi, the U.N. Protection Force chief, called on the United States and other NATO countries to send 10,650 troops, 500 civilian police and 150 military observers to bolster the 12,000 U.N. troops already in Bosnia.

“This window of opportunity which has opened in Bosnia-Herzegovina, including Sarajevo after so many months of efforts and anxiety, might close in the absence of additional resources,” Akashi warned.

Gen. Jean Cot, the French military commander of the 29,000-strong U.N. Protection Force, targeted the United States in his appeal for troops that could be deployed quickly.

“What I need is to have troops available immediately, and those nations which are in a position to send troops immediately can be counted on the fingers of one hand,” Cot said, apparently referring to the United States, Britain and France. “As for the rest, it’s dreaming. It’s for next year.”

The appeals by Akashi and Cot were directed at the United States, which has repeatedly stated it will not send ground troops to Bosnia unless a peace agreement is negotiated and endorsed by all three warring factions. Cot criticized the American position as “not very courageous.”

Last month, Cot redeployed hundreds of troops that had been patrolling Serbian-occupied areas of Croatia and Bosnia into Sarajevo as a stopgap measure to monitor compliance with a NATO ultimatum that all heavy artillery be withdrawn by Feb. 21 from a 12-mile radius of the Bosnian capital, be placed under U.N. control or face punitive air strikes.

Cot stressed that the redeployments were an emergency measure and warned that leaving the troops’ original posts uncovered invited a rekindling of fighting in those areas and a general escalation of the Balkan conflict.

“We did what one does in case of a fire: We sent people there as quickly as we could,” Cot said. “But this also means taking away troops from Croatia . . . which could imply some risks that could not be borne for too long.”

Even with the reassignment of almost 1,000 more troops to the Bosnian capital, where 3,000 U.N. peacekeepers operate a humanitarian airlift and observer mission, the job of securing and dismantling the hundreds of Serbian artillery pieces still within the exclusion zone has overwhelmed the U.N. mission.

Increasing numbers of cease-fire breaches have been reported each day over the last week, posing the risk of a return to artillery shelling of the capital where more than 10,000 people have been killed since Serbs began their armed rebellion against Bosnian independence in March, 1992.

So desperate was the appeal for reinforcements that Akashi said the United Nations is now willing to accept troops from Turkey and other countries previously deemed to be too burdened with historical or religious ties to the region.

Turkey had offered to send troops in the past, but objections were raised by Serbian rebel forces that continue to resent that country for its 500-year occupation of the Balkans and accuse it of partiality toward Bosnian Muslims.

“We should not be as stringent as we used to be as to choice of nations,” Akashi said. In Washington, State Department spokesman Mike McCurry said there is no change in the Administration’s refusal to send ground troops to Bosnia before the warring factions agree to a durable peace.

Times special correspondent Kirka reported from Zagreb and Times staff writer Williams from Vienna. Times staff writer Norman Kempster in Washington contributed to this report.