The State Department yesterday abruptly postponed a scheduled meeting of the committee that coordinates the huge U.S. program of military aid to Israel. The move seemed certain to stir speculation throughout the Middle East that it was intended to put pressure on the Jewish state.

"Absolutely not," State Department spokesman Richard Boucher said last night when asked whether the United States was sending a new signal of impatience at the reluctance of Prime Minister Yitzhak Shamir's new rightist government to show flexibility in the Mideast peace process.

Boucher and other officials said that Secretary of State James A. Baker III had ordered postponement of the annual session of the Joint Security Assistance Planning Committee, which had been scheduled to begin here Tuesday, because the size of America's aid commitment to Israel next year is an issue in the ongoing budget summit between the White House and Congress.

The officials said Baker had decided that the meeting of diplomats and military officers from the two countries would not be able to make any meaningful decisions now about the use of the eventual U.S. aid that will flow in the fiscal year ahead. They said Baker felt it made more sense to wait until September when the administration expects to have a better idea of whether Israeli military aid for the 1991 fiscal year will differ substantially from this year's level of $1.8 billion.

Boucher said "It was mutually agreed" with the Israelis to wait. "The postponement is purely a practical matter," he said. "U.S.-Israeli relations remain strong, and our commitment to Israel's security remains unshakable. We look forward to holding the meeting in September."

However, several U.S. officials acknowledged privately that the explanation, even if true, is unlikely to prevent concern in Israel about whether its special relationship with the United States is being damaged by differences between the administration and the Shamir government over how to get a dialogue going between Israel and the Palestinian inhabitants of the West Bank and Gaza Strip.

Some officials, noting that senior department policy-makers dealing with the Middle East were reluctant to discuss the matter, said Baker might not be unhappy if his action created an atmosphere of uncertainty in Israel about the state of the U.S. relationship.

Ties between Washington and Jerusalem have been frayed since last spring when Shamir rejected Baker's proposals for arranging the dialogue. Shamir's move caused the breakup of his coalition with the Labor Party and, after long delay, resulted in his forming a new, narrowly based government with rightist nationalist and religious forces strongly opposed to giving up Israeli control of the territories.

In testimony before the House Foreign Affairs Committee on June 14, Baker put Shamir on notice that the United States will not go through another laborious attempt to intercede in the peace process unless it is convinced that the Israelis sincerely want talks. However, when Shamir later responded to a letter from President Bush asking for clarification of his government's views, he gave no sign of willingness to offer concessions that would attract Palestinians to a dialogue.

Baker subsequently invited the new Israeli foreign minister, David Levy, to meet with him in Paris earlier this week, but Levy, who is recovering from a mild heart attack, was unable to make the trip. In the meantime, some U.S. officials have said that Bush and Baker, while unwilling to challenge Shamir openly, are growing impatient at what they suspect is an Israeli attempt to hold the United States off as long as possible.

In an ironic counterpoint to yesterday's action, the first cabinet-level contact between the administration and the new Israeli government will take place here today when Defense Minister Moshe Arens pays a courtesy call on Defense Secretary Richard B. Cheney. However, while Arens is a former foreign minister and close confidant of Shamir, Israeli sources said his talks here will be limited strictly to defense questions and will not touch on the peace process.