PLO chief Yasser Arafat said Thursday he is convinced the Bush administration favors in principle convening an international Middle East peace conference.

His comments came one day after U.S. and PLO representatives talked for 4 1/2 hours in their first formal meeting since Bush took office.The United States talked about reducing tension in the Israeli-occupied lands, but the PLO vowed the Palestinian uprising will not let up until Israel withdraws from the territories.

Arafat told reporters Thursday that the Palestine Liberation Organization believes the only solution to the Middle East crisis is an international conference involving all of the parties, including the PLO, Israel and the five permanent members of the U.N. Security Council.

"As for the American administration, they are for an international conference in principle but say it should be very well prepared," the PLO chairman asserted.

Israel opposes the idea of an international conference, as it does the American decision to talk with the PLO. The Reagan administration, while not enthusiastic about an international conference, said such a conference could be helpful if it led to direct Arab-Israeli talks.

Arafat, speaking to reporters in a PLO office, said a leadership meeting was held Wednesday night.

"Our evaluation, one, is that we consider that the content of the meeting was a positive one and, second, it was a serious one in so far as the topics on the agenda were concerned," said Arafat, wearing his traditional Arab headdress and green military uniform.

"We consider the meeting an indication of the new American administration is seriously interested in this PLO-American dialogue."

Officials at the U.S. Embassy in Tunis refused to discuss the meeting and referred all queries or requests for comment to the U.S. State Department.

Arafat said it was Israel's responsibility to ease tension in the West Bank and Gaza Strip, where more than 400 Palestinians and 17 Israelis have died in the 15-month-old uprising.

"I understand that a request for reducing tension is directed at Israel because Israel is causing the tension - not only the army, but settler groups using arms against Palestinians," Arafat said.

A first contact between the United States and the PLO occurred Dec. 16, shortly after Washington reversed a 13-year policy of refusing to deal with the PLO. That decision followed Arafat's public renunciation of terrorism and recognition of Israel's right to exist.

Wednesday's session was the first to get down to the substantive issues of peace and conflict in the Middle East - terrorism, negotiations and who represents the Palestinian people, delegates from both sides said.

Israel rejects the PLO as a terrorist organization.

Asked by reporters if the United States demanded the PLO put an end to the uprising, Arafat said, "No such request was presented by anyone, and no one can ask us to do that. No one can stop a people from resisting occupation."

No date for a further session was announced, but both American and PLO officials said they fully expected the talks to continue.