Palestinian leader Yasser Arafat, after nearly seven hours of meetings here with Soviet Foreign Minister Andrei Gromyko, said today that the United States is determined to undermine the Geneva Middle East peace talks.

Arafat, the leader of the Palestine Liberation Organization, also denounced Israel, saying it intends "not to recognize the national rights of the Palestinian Arabs and the PLO."

Arafat, who until the last year had access only to lower-level Soviet diplomats because he does not represent a state, is here just before Gromyko's schedule talks with U.S. Secretary of State Cyrus Vance in Vienna next week. Those talks are to include discussions of the Middle East as well as problems in achieving a new strategic arms limitation agreement.

The Soviet Union is vigorously pushing a resumption of the Middle East conference in Geneva, which met only once - for two days in December 1973 - before being adjourned.

In an interview published today by the official Soviet news agency, Tass, Arafat said that Vances recent peace-seeking swing through the Middle East "caused an aggravation of the situation" because Vance "tried to disregard fully the Palestinian problem, which is known to be the cornerstone for any Middle East settlement."

According to Tass, the PLO leader said that "Vance's mission has shown that the United States has not given up its plans if not of torpedoing the Geneva conference, then if possible of emasculating its meaning [by] striving to bar the Soviet Union from participation in the Middle East settlement."

A key point in both Moscow's and Washington's proposals is whether the PLO will be recognized and participate in any peace conference. The PLO, representing millions of Palestinians who are stateless in their own eyes, has mixed terrorist tactics and intense diplomacy over the years to press its claims of nationhood.

Diplomatic sources here noted that Arafat avoided comment on United Nations Resolution 242 which regonizes Israel's right to exist. The sources suggested that Arafat may have been signaling some flexibility on the question.

Last week, the PLO rejected an American proposal that the Palestinians drop their opposition to the resolution as a condition of being included in the new peace talks. One Western diplomatic source said he believes that the Soviets are interested in moving the PLO toward acceptance of Resolution 242, but must be able to offer the PLO something in return. The Soviets have frequently said they accept Israel's right to exist and would join with the United States and other Western powers to guarantee its sovereignty. Such a pledge was part of President Leonid Brezhnev's definitive Middle East policy statement in March.