Secretary General Kurt Waldheim, in a move opposed by Israel and the United States, has summoned the General Assembly to a special emergency session today on the Palestinian issue.

Waldheim scheduled the session yesterday after 90 Arab and Third World countries -- more than the required 50 percent of the 152-member General Assembly -- requested it.

Arab countries have prepared a tentative resolution affirming once more the Palestinians' right to set up their own state and calling for Israel's withdrawal, beginning Nov. 1, from the occupied territories including East Jerusalem. It also requests Waldheim to set up a U.N. pearcekeeping force to supervise the withdrawal and to turn the territories over to the Palestine Liberation Organization.

The United States argued unsuccessfully that the session was unnecessary because the issue has been discussed frequently by the General Assembly and is on the agenda for the regular fall session.

Israel and the United States also dispute the Arabs' contention that the emergency assembly session can legally enforce any decision it makes.

The Arabs, angered at repeated U.S. moves in the Security Council to block anti-Israeli resolutions, contend that the session is being called under a 30-year-old resolution that transfers some functions of the Security Council to the assembly if the council is stalled by a big-power veto. Ironically, the United States initiated that device in the early postwar years to get around repeated Soviet Vetoes in the Security Council.