BRUSSELS, Belgium (AP) _ NATO's ``partnership for peace'' with Russia got off to a rocky start Friday. Moscow failed to send a defense leader to a high-level meeting of former Cold War foes, and the official they did send expressed concern about Western plans to help peacekeepers in Bosnia.

The Russians also called off a one-on-one session with U.S. Defense Secretary William Perry.

Moscow was represented at the meeting at NATO headquarters by its local ambassador, Vitaly Churkin.

The meeting was closed, but a NATO official said Churkin had raised concerns about the French-British rapid reaction force being created to reinforce U.N. peacekeepers.

Churkin said the force's presence in Bosnia must not lead to military escalation, and he also expressed concern about the heavy weapons its members would have. NATO defense ministers unanimously endorsed the reaction force on Thursday.

Still, Willy Claes, the NATO secretary general, dismissed suggestions that the Russians might object to United Nations actions enabling reinforcement of the peacekeepers.

``I did not hear one negative sound during our meeting,'' Claes told reporters.

After the meeting, Perry said, ``It is hard to make forecasts, but to my knowledge the Russians will support'' creation of the force.

Defense Minister Pavel Grachev had been scheduled to attend the one-day session in Brussels, but instead he accompanied President Boris Yeltsin to Ukraine for discussions on a dispute over the former Soviet Black Sea navy fleet. No one else from the Ministry of Defense was sent as Grachev's replacement.

U.S. officials acknowledged their disappointment but tried to put the best face on what some saw as a snub of NATO's year-old effort, the ``partnership for peace,'' to create closer ties to non-NATO countries, especially Russia.

``I understand the reason for Minister Grachev not being here,'' Perry told a news conference. ``Of course I would have liked to have had Minister Grachev here,'' not only for the meeting but for a scheduled one-on-one session, he said.

Perry noted that he expected to see Grachev in Moscow later this month.

The meeting was attended by defense chiefs of all 16 NATO nations except France, which as a matter of policy is not part of NATO's defense structure, plus 23 countries of the former Soviet Union and Warsaw Pact.

Joseph Nye, assistant secretary of defense for international security affairs, told reporters the meeting was especially important because it was the first with former East bloc nations since Russia formally agreed at a NATO session in the Netherlands last week to join the partnership for peace program.

Instead of sending Grachev or a deputy, the Russians were represented here by Churkin, their ambassador to Belgium, the European Union and NATO.

In a brief corridor conversation, Churkin was asked why a defense ministry official was not sent. ``An ambassador is a very important representative of his country, don't you think?'' he replied with a wink.

Russia's relations with NATO are particularly sensitive because Moscow is upset that the Western alliance intends to expand eastward to include some former Warsaw Pact nations. Russia sees this as a potential threat to its own security.

Ashton Carter, assistant defense secretary for security policy, said Perry had wanted to have a one-on-one meeting with Churkin, since Grachev couldn't make it, but that the Russians called it off. Carter said Churkin told him he had assumed the planned session was off because Grachev was gone.

Perry had intended to discuss a range of issues with Grachev, including asking for a Russian commitment to participate in a multinational military exercise this summer in Louisiana under the auspices of the partnership.