Thousands of fist-waving Iranians demonstrated outside U.S. Embassy today to denounce the deposed shah's flight to Egypt, a move that Foreign Minister Sadegh Ghotbzadeh said made resolution of the American hostage crisis "extremely difficult."

In a news conference after about 50,000 Iraninas had gathered at the occupied embassy in response to a government call for protests, Ghotbzadeh called Mohammad Reza Pahlavi's flight from Panama to Egypt "a moral victory for the Iranian case against the deposed shah."

He said the move showed that Iran's case for the shah's extradition from Panama was strong. Iran filed extradition papersd in Panama yesterday, a day after the shah's departure.

Ghotbzadeh also asserted that the Soviet Union has accepted in principle Iranian proposals to open regional negotiations on the withdrawal of Soviet troops from Afghanistan.

He stressed, however, that no date for initiating negotiations had been set.

Ghotbzadeh predicted that the shah's presence in Egypt would cause problems for President Anwar Sadat and "a tremendous amount of unrest" there. "I am sure the Egyptian people will not tolerate the presence of such a criminal as a guest of their government," Ghotbzadeh said.

In the streets outside the U.S. Embassy, demonstrators shouted, "People of Egypt, rise and overthrow Sadat," and "The shah must be returned and executed."

The demonstration at the Tehran embassy, much smaller than some previous ones, featured the now standard anti-U.S. chants and slogans, a burning of the American flag and the presence in wheelchairs of three Iranians crippled during the Revolution. Some anti-Soviet slogans were also heard.

Similar demonstrations were reported in the holy city of Qom and other provincial centers.

For the first time since the embassy was seized Nov. 4, large numbers of Moslem clergy were clearly visible both inside and later outside the compound as if to signal that their close identification with the militant student captors was no longer a secret.

Equally significant, for the first time in months, the government-controlled television sent mobile units to film the proceedings at length.

It was as if a decision had been made to provide maximum exposure for the students, whose access to radio and television had been restricted in recent weeks.

At his news conference Ghotbzadeh suggested than there would be a less favorable mood in the new parliament in discussing the hostage crisis. The parliament, to convene some time next month, has been entrusted by Ayatollah Ruhollah Khomeini with settling the hostage issue.

Ghotbzadeh promised to "continue to work and strive for a peaceful solution" of the hostage problem. He expressed confidence that "we are going to succeed."

But he warned the shah's move "has been a blow to the whole case" and said that Iran's recent public willingness to trust international law and international bodies has been "extremely damaged."

Ghotbzadeh obviously sought to avoid outright criticism of the possible U.S. government involvement in the shah's flight from Panama.

"We don't have precise information," he said. "What is certain is that the Carter administration has not prevented this fugitive run. If the U.S. government really wanted to prevent this escape they had the means and ways to to it."

On the Iranian proposal for regional negotiations on the pullout of Soviet troops from Afghanistan, Ghotbzadeh said he had proposed the talks about three weeks ago to Soviet Ambassador Vladimir Vinogradov and that the Soviets had accepted in principle 10 days ago.

Suggested participants, he said, were the Soviet Union, the Moscow-imposed Afghan government, the Afghan "freedom fighters," Pakistan, "possibly China" and Iran.

Insisting that Iran was now providing only "limited help" to the Afghan rebels, he said that if the proposed negotiations fail and the Soviet troops remain, "we are going to give everything we possibly can to help the Afghan freedom fighters have their own rights."

Indicative of the still exploratory nature of the proposed talks was the minister's admission that neither Pakistan nor Afghanistan has been approached because of the week-long Iranian new year holiday scheduled to end Wednesday.

In light of the Soviet rejection of seemingly similar European plans to solve the Afghan problem, observers expressed doubt that the Iranian initiative would be successful.