Russia has tried to secure overflight rights from several Central European nations to ferry more peacekeeping troops into Kosovo's main airport, but the idea was rejected by NATO and U.S. officials who are growing increasingly distrustful of Russia's intentions in the Balkans, officials said last night.

According to a senior Pentagon official, NATO officials decided to intercede in Russian efforts over the last two days to get overflight permission from Bulgaria, Romania and Hungary because Moscow has not agreed to abide by a deal putting its peacekeepers under NATO's command.

Yesterday, Gen. Wesley K. Clark, NATO's top commander, informed the Russians after consultations with NATO's political leaders that Russia would not be allowed to add to the 400 troops already stationed in Kosovo until it agrees to honor the original terms signed in Helsinki last month.

Since then, the Russians, who will be permitted to bring 3,600 troops into Kosovo as part of the peacekeeping operation, have been trying to renegotiate their role in the Yugoslav province, according to NATO and U.S. officials.

At Helsinki, Russia agreed to scatter its troops at the Pristina airport and in sectors under the control of U.S., British and German commanders. But it has since sought to renegotiate the terms of the deal. Essentially, said U.S. officials, Russia wants its military units to be stationed contiguously, creating a de facto sector.

"There can be no changes unless they're agreed to by the confirming parties" of the Helsinki accord, NATO and Russia, Defense Secretary William S. Cohen said at a Pentagon briefing Thursday.

Clark also said at that news conference that the Russians wanted territory that did not include as many Kosovo Liberation Army members. The KLA, which has sought an independent Kosovo and fought against Serb forces during the 78-day war, likely would be hostile to any Russian presence. Russia was firmly opposed to the recent NATO bombing campaign.

Some U.S. officials believe that Russian officials are playing to domestic demands that Russia receive a greater, autonomous hand in the peacekeeping operation because of its significant role in persuading Yugoslav President Slobodan Milosevic to agree to NATO demands concerning Kosovo, and that national officials want to show that the Russian military, severely weakened by the country's poor economy, is nonetheless a power to be reckoned with.

But after Russian troops in Bosnia moved into Kosovo unexpectedly last month and took over the Pristina airport, and after Moscow sent a pair of strategic bombers near Iceland and within striking range of the United States during military exercises a week ago, U.S. officials are in no mood to cater even to Russian domestic concerns.

"It's NATO's position that they signed an agreement at Helsinki," said one Pentagon official. "Now they want more, they want to set up their own quasi-sector. It's like a professional athlete who signs a five-year contract and wants to renegotiate before they start the game."

The Russians are to resume talks with Clark on Tuesday, but NATO, with the strong backing of the United States, has agreed to block their entrance into Kosovo until they have agreed to the original terms.

NATO's decision to block Russia's attempt to bring in more troops was reported first in today's editions of the New York Times. It said Russia had asked but was denied permission from the three countries to fly 10 planes over their airspace on Sunday.

Under the original agreement, Russia was to begin moving more troops into Kosovo this weekend, but the Pentagon said U.S. officials have grown distrustful of Russian motives and did not want to grant Moscow any leeway during the upcoming three-day weekend, when many senior U.S. officials will be away from Washington.