Breaking a general Arab silence on the U.S. landing in Iran, Egyptian President Anwar Sadat today urged President Carter not to be "disheartened" by the results of the operation and renewed his offer to help in any future attempt to rescue the American hostages in Iran.

Sadat refused to discuss reports that American aircraft used Egyptian bases to mount the raid into Iran, but military analysts in Cairo suggested that U.S. AWACS radar control planes flew from an Egyptian air base at Kenna, near Luxor in Upper Egypt, to jam Iranian radar and to guide U.S. transport planes and fighters covering them.

Sharp criticism of the U.S. operation came from Pakistan, a non-Arab nation that the Carter administration has courted ardently with aid offers in recent months, and from Syria, the Soviet Union's most important Arab ally.

Pakistan promised to stand by Iran in its "struggle to defend its sovereignty and national honor," a Foreign Ministry spokesman said Friday in a statement expressing "shock and dismay" at the "adventurous" American move. The United States strengthened security measures at U.S. diplomatic facilities in Pakistan.

Syria's official radio accused Sadat of cooperating with the United States and Israel in mounting "an act of piracy and aggression" against the Iranian revolution. Arab regimes friendly to the United States remained silent throughout the Friday holy day.

Israeli officials, meanwhile, denied that the Jewish state had participated in the abortive rescue attempt. Prime Minister Menachem Begin expressed his country's sorrow over the deaths caused by the mission, adding, "They tried to save their hostages. There was a problem. It could happen to anybody."

Speaking to reporters in his hometown village of Mit Abul Kom 40 miles northwest of Cairo, Sadat sounded the same note of sympathy for the mission, which he called "hard luck."

"But it should not dishearten more action to free and rescue the hostages," Sadat continued. "I have promised the American people that I shall give facilities for the rescue of the hostages and for the rescue of any Arab state on the Gulf. This is my policy."

But Sadat, who has been severely criticized throughout the Islamic world for signing a peace treaty with Israel and attached by the Iranian rulers for giving deposed shah Mohammad Reza Pahlavi asylum, stepped away from reporters when asked if Egypt had participated in the rescue effort Thursday night.

The strong alliance that has developed between Carter and Sadat was reflected by the fact that the president's mother was in Cairo when the news of the aborted raid came. "Poor Jimmy," she sighed when told. Mrs. Carter called off a scheduled news conference.

The Egyptian leader's embrace of the fallen shah also has drawn wide criticism in the Arab world, much of which is sympathetic to the Iranian revolution because of Islamic solidarity with Ayatollah Ruhollah Khomeini's call for a return to basic Moslem principles.

Sadat, however, has firmly aligned his government with the United States, on this as well as the peace treaty with Israel. His expressions of willingness to help Washington against Iran were part of an increasingly close military cooperation between Egyptians and Americans, including extensive U.S. arms aid.

The American AWACS have been using facilities at Kenna regularly since the beginning of the year, sometimes flying missions over the Persian Gulf. During joint exercises with Egyptian personnel in January, about 150 American AWACS crewmen and maintenance specialists were assigned to the Kenna base.

Although Israeli Radio quoted air traffic monitors as saying U.S. C130s flew toward Iran out of the Cairo air base, military analysts here said they were more likely to have used Kenna as their departure point.

The Egyptian government, however, declined any confirmation of the foreign anaylsts' assessments. Defense Minister Kamal Hassan Ali refused to comment and Prime Minister Mustafa Khalil said he had not been informed of any Egyptian role in the operation.

The Israeli reports fixing Egypt as the departure point also raised questions about cooperation by other Arab states, particularly Saudi Arabia and Behrain. To reach the Gulf from Egypt the U.S. C130s would have to fly across Saudi Arabian airspace. In addition, according to the Israeli broadcast, the U.S. planes made a refueling stop in Bahrain.

Previous declarations by Saudi and Bahraini officials have emphasized opposition to any foreign intervention in the Gulf area, including a military strike such as that mounted last night or a naval blockade, also reported under consideration in Washington.

At the same time, Bahrain's hereditary ruler allows the U.S. Navy to use port facilities in his island nation and Saudi Arabia is reported willing to cooperate with regional U.S. security measures as long as they do not involve U.S. military presence within the kingdom.

Observers noted that the sultanate of Oman also has agreed to allow Washington "facilities" for Gulf security. U.S. C130s have for some time been using an Omani air base to fly in equipment for U.S. Navy ships in the nearby Gulf of Oman. U.S. helicopters have been seen ferrying the supplies from near the Omani capital of Muscat out to ships at sea.