Dispute Delays Air Strikes in Bosnia : Balkans: White House warns of likely action. But U.N. veto of NATO’s request for attacks underscores difficulties.

The White House warned Saturday that NATO air strikes may be inevitable to halt a rebel assault on a Bosnian enclave, but senior U.S. officials acknowledged that retaliatory action had already been delayed a day because of a dispute between NATO and U.N. officials.

After a day of hectic diplomacy that underscored the difficulties of coordinating a military operation burdened with several layers of command, a senior Administration official confirmed that the United Nations had vetoed a NATO recommendation to commence the air strikes Saturday in retaliation for Bosnian Serb attacks on Gorazde that violated a North Atlantic Treaty Organization ultimatum issued Friday.

In an effort to play down the U.N.-NATO disagreement as merely a temporary “delay” that would not undermine the allies’ resolve, the official said the Clinton Administration was “close to an agreement with the U.N. on how to proceed” with air strikes.

U.S. officials also stressed that the Serbs should not “misread” the delay as a sign of weakness or lack of resolve, adding that strong punitive measures are “inevitable” if the Serbian forces continue to defy the NATO ultimatum. Air strikes “are only a matter of time unless they comply,” one senior official said.

Throughout the day, Clinton Administration aides sought to minimize what had been an embarrassing and inauspicious start to NATO’s efforts to agree with the United Nations on the timing of what would clearly be a major escalation of U.S. and allied military involvement in Bosnia’s 2-year-old civil war.

Meeting in Brussels on Friday, NATO officials set three deadlines for Bosnia’s rebel Serbs. The first called for an immediate cease-fire, which U.S. and U.N. officials said the Serbs continued to violate throughout the day. The second deadline, which expired at 2:01 a.m. today (5:01 p.m. PDT Saturday), mandated the withdrawal of all Serbian forces from the embattled city to an area at least 1.9 miles away. The third deadline gives the Serbs until 2:01 a.m. Wednesday (5:01 p.m. PDT Tuesday) to move all their heavy weapons at least 12 miles away from Gorazde.

If the Serbs do not abide by these conditions, the allies threatened, NATO’s Southern Command would be authorized to conduct air strikes against heavy weapons and other military targets within a 12-mile radius of Gorazde. But the agreement also specified that the United Nations would have to approve the air strikes before they went ahead--a condition that provoked a behind-the-scenes crisis Saturday.

Because the Serbs continued to shell Gorazde after the NATO ultimatum was issued, Adm. Leighton Smith, the NATO commander for Southern Europe, asked for permission to launch the air strikes before the withdrawal deadline expired, U.S. and U.N. officials confirmed. But arguing that the Serbs with whom he was negotiating in Belgrade needed more time to comply with the ultimatum, Yasushi Akashi, the chief U.N. representative in the region, refused.

A senior U.S. source acknowledged that both U.S. officials and NATO commanders were furious with Akashi’s veto, fearing that it would send “precisely the wrong message to the Serbs that NATO was not serious” about carrying out its ultimatum.

The dispute underlines what critics said are the immense problems posed by giving the United Nations veto power over military decisions involving U.S. and other NATO forces.

“We are trying to run a war in which you have about 12 layers of decision-making, and it’s proving to be pretty difficult,” said former Secretary of State Lawrence S. Eagleburger, who was interviewed on CNN’s “Newsmaker Saturday.”

Times staff writer Tyler Marshall in Brussels contributed to this report.