With Soviet physicist Andrei Sakharov at his side, President Reagan said Monday the restriction of human rights in the Soviet Union will impede progress in superpower relations "until it's completely eliminated."

During an Oval Office photo session with Sakharov, the scientist confined to seven years of internal exile for advocating human rights, Reagan said U.S. efforts to expand freedoms in the Soviet Union have had great success.Reagan was told by Sakharov that political prisoners remain in Soviet jails, though he gave credit to Soviet President Mikhail Gorbachev for having been more cooperative than any Soviet leader before him.

"Most political prisoners have now been freed in the Soviet Union," Sakharov said through an interpreter, "and this is partly your doing as well."

However, Sakharov said it was "very ironic" that even as he was allowed freedom of travel by the Kremlin, a man imprisoned for protesting his exile to Gorky nine years ago continued to be jailed.

When asked whether the human rights issue continues to be an irritant to improved U.S.-Soviet relations, Reagan replied, "Of course, until it's completely eliminated."

Noting recent Soviet statements that raised expectations of a total release of political prisoners, Reagan said, "We can only wait and see."

Sakharov called the meeting "a great event for me" and said he talked to Reagan about human rights and political prisoners.

"The meeting was a very substantive one," he said, adding that Reagan "made a great personal impression on me." Sakharov met briefly with reporters before being bustled into a large white limousine for a round of other appointments in Washington.

Reagan has made human rights a major element of U.S.-Soviet relations. U.S. officials welcomed the meeting with Sakharov, who is traveling under the auspices of a Moscow-based human rights organization, as a hopeful sign of Gorbachev's commitment to correct past abuses.