President Carter summoned congressional leaders to the White House late yesterday amid indications he will soon dispatch U.S. Air Force airborne warning and control aircraft to Saudi Arabia to aid the air defense of the Persian Gulf.

Lawmakers who took part in the special 1 1/2-hour briefing by the president and his senior advisers forecast an announcement of new U.S. efforts in the Iraq-Iran within a few hours.

Defense officials said the deployment of the U.S. air defense aircraft to Saudi Arabia is highly likely, but that a final decision awaits the approval of an announcement acceptable to both countries. It was unclear last night whether the Saudis requested the deployment, or whether it was a U.S. initiative.

Yesterday afternoon's White House meeting, involving Secretary of State Edmund S. Muskie, Secretary of Defense Harold Brown, CIA Director Stansfield Turner, presidential assistant Zbigniew Brzezinski and other top officials in addition to Carter, was the latest of a series of top-level conclaves over the past two days regarding the continuing war in the Persian Gulf.

U.S. consideration of the military deployment followed increasingly explicit threats by Iran to take action against any Persian Gulf Countries cooperating with the military forces of its enemy, Iraq. These statements have generated concern in several small Persian Gulf oil sheikdoms, as well as in Saudi Arabs, that Iran might bomb their oil fields, refineries or other facilities in a new extension of the Iraq-Iran war.

The Air Forces planes, called AWACs, are modified versions of the Boeing 707 jetliner and carry sophisticated radars that can see electronically about 250 miles in all directions. Thus, stationed over Saudi territory, they could detect any warplanes approaching the west side of the Persian Gulf and could assist in directing their interception by defense forces.

The Carter administration dispatched two AWACs planes and about 250 U.S. Air Force personnel to Saudi Arabia in March 1970 when the war between North Yemen and South Yemen, on the Saudi border, created concern that the fighting might spill over to the oil kingdom. When the fighting subsided, the planes and U.S. personnel returned home.

After a private briefing by Muskie in New York earlier yesterday, chairman Frank Church (D-Idaho) of the Senate foreign Relations Committee issued a statement approving of the supply of "defensive assistance" to Saudi Arabia in present circumstances.

Church also said, "we should hold our Navy ready if needed to participate in keeping open the Strait of Hormuz, should a naval presence become necessary either for the purpose of keeping the strait open or to protect oil tankers." Church said such a naval presence might involve the participation of British, French and Australian vessels as well as those of the United States.

Muskie conferred in New York early yesterday with representatives of Bahrain and Oman, two Persian Gulf states that could be threatened by a widening of the Iraq-Iran war. There was no report on whether Muskie discussed with them the possible dispatch of the U.S. air defense aircraft.

The secretary of state also saw Pakistani Foreign Minister Agha Shahi, whose chief of state, President Mohammed Zia ul-Haq, has traveled to Iran and Iraq on behalf of the Islamic conference of states in an effort to encourage mediation efforts that would end the fighting. Zia is expected to arrive in New York today to visit the United Nations, with a side trip to Washington later this week.

Zia's mission to the two combatant states failed to bring any indication of a halt to the fighting in the near future, and there was doubt in diplomatic circles that a cease-fire could soon be arranged.

As seen by State Department officials monitoring reports from the war zone, the prospect is for a relatively lengthy war. Both Iran and Iraq now seem to be seeking the over-throw of the ruling powers in the regime of the other as a central objective, these sources said. While the downfall of Iraqi President Saddam Hussein or Iran's Ayatollah Ruhollah Khomeini cannot be ruled out in time, these are unnegotiable objectives.

The damage to oil refineries and other oil installations in both Iraq and Iran during a week of fighting is believed to be extensive. And as Iraqi troops move in measured but deliberate pace further into the Iranian oil province of Khuzestan, there is no lessening of the danger of additional damage to the petroleum assets on both sides.

Two principal flashpoints could bring a dramatic widening of the war to outside powers, in the view of Washington officials.

One is the possibility of Iranian air strikes against states in the area which, in Tehran's view, are aiding Iraq. In an interview broadcast yesterday on Tehran Radio, Iranian Prime Minister Mohammed Ali Rajai said his country has warned the United Arab Emirates, Kuwait, Jordan "and other similar states" that Iran will consider that it is at war with them if they continue aleged aid to Iraq.

The other possibility is Iranian action to shut off the flow of oil tankers through the Strait of Hormuz, thus striking at the vital petroleum lifeline of many western nations. Iran has permitted tankers to proceed through the strait so far, so long as they do not put in at Iraqi ports. The commander of the Iranian navy, Admiral Afdal, was quoted on Tehran Radio yesterday as saying that his forces are now "in complete control" of the strategic strait.