The first official direct talks between American and PLO officials opened Friday in suburban Tunis. The United States made clear beforehand that it would be watching PLO actions to curb terrorism in the Middle East.

Reporters and photographers were admitted for the ceremonial beginning of the talks between delegations led by U.S. Ambassador Robert H. Pelletreau Jr. and Hakam Balaoui, the PLO representative in Tunis. The meeting at a villa in suburban Carthage then continued behind closed doors.Western diplomatic sources in Tunis said earlier Friday that there would be no detailed exchanges at the meeting and that afterward it was likely there would be "a period of assessment."

The American side planned to open the meeting with a clear statement of Washington's attitude toward terrorism and say the United States expected PLO chairman Yasser Arafat's words would be matched by his actions, a high-ranking diplomatic source said.

Secretary of State George P. Shultz announced Wednesday that Arafat's recent statements renouncing terrorism and accepting Israel's right to exist in peace met the conditions for reversing a longstanding U.S. policy of refusing any direct dialogue with the Palestine Liberation Organization.

The United States expects that the PLO's renunciation of terrorism will be "prominent and pervasive," a diplomatic source said, but also understands that Arafat does not control all Palestinians, nor all acts of terrorism.

The sources said Washington would expect the PLO to dissociate itself clearly from any future acts of terrorism.

The second American agenda item, according to the sources, will be a statement of Washington's general principles and approach to Middle East peace.

Pelletreau, once held hostage by Palestinians, telephoned PLO headquarters Thursday to make the initial contact, according to the PLO and U.S. Embassy spokesman Adnan Siddiqi. Shultz designated Pelletreau as the U.S. government's "only authorized channel of communication" with the PLO.

Siddiqi would only say that Pelletreau, 53, had a short conversation with a PLO official at the organization's headquarters in Tunis. He did not identify the Palestinian or give

details of the discussion.

Friday in Tunis, Palestinian flags appeared in the front of many homes and businesses, news reports said.

Arafat was not in Tunis, and it wasn't known when he would return. He met East German leader Erich Honecker in Berlin on Thursday before heading to Romania.

East Germany was one of the first countries to recognize the independent Palestinian state declared by PLO leaders at a meeting last month.

Pelletreau, ambassador to Tunisia since March 1987, is one of the most experienced and knowledgeable American diplomats on Arab affairs.

The Long Island native speaks Arabic and French and has served in Algeria, Morocco, Mauritania, Lebanon, Jordan and Syria. He once was ambassador to Bahrain.

His first encounter with Palestinian terrorism came in September 1970 when guerrillas of George Habash's extremist PLO faction diverted three airliners to Amman, Jordan, and took the passengers and crews hostage. He later escaped.

PLO envoy OK'd

The credentials for the first ambassador of the newly declared Palestine state have been accepted, the Algerian foreign ministry said Friday. Mondher Azeddine Dejani has been accredited to Algeria, the first country to recognize the new state.