The United States has agreed to send a three-star general to an informal meeting Monday of the U.N. Security Council's military arm, but U.S. and diplomatic sources stressed yesterday that the session was intended more as a gesture to the Soviet Union for its cooperation in the Persian Gulf crisis than a move toward a unified United Nations military command.

However, the sources said, the meeting of the Military Staff Committee, which they described as "informal consultations," is intended to explore other ways of expanding the committee's role, such as coordinating the activities of the different national forces confronting Iraq in the gulf region and possibly institutionalizing these new powers so the committee can be more active in the future.

Since Iraq's Aug. 2 invasion of Kuwait, the Soviets have been pressing for a larger role for the long-moribund military committee, which the United Nations Charter designates as the world body's highest military authority. It is supposed to be composed of the highest-ranking military officers from each of the council's five permanent members: the United States, the Soviet Union, Britain, France and China.

The original intention was for the committee to direct any military forces established by the council. But, during the years of Cold War division between the superpowers, the council was too divided to agree on any joint military activities, and the committee has held only brief, pro forma meetings of officers with no higher rank than colonel.

The council has put a U.N. military umbrella over the economic embargo against Iraq and Kuwait by authorizing nations with warships in the gulf to use force to halt vessels seeking to evade the blockade. However, the United States, Britain and France have been opposed to surrendering direct control over their forces in the region. U.S. commanders are especially concerned about the wisdom of an unorthodox chain of command seeking to run the huge force of American, European and Arab troops assembled in Saudi Arabia.

The sources said the Bush administration will seek to demonstrate that it takes seriously the Soviet interest in revitalizing the committee by sending a lieutenant general to act as the personal representative of Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff.

The sources said Britain tentatively is expected to send a two-star general from the military staff attached to its Washington embassy, and the Soviet Union and France also are expected to have representatives of similar rank. China's plans were unknown, the sources added.