President Reagan held an emotional meeting with Soviet dissident Andrei Sakharov yesterday at the White House and said that Soviet human rights abuses are impeding progress in relations between the superpowers and would continue to do so until the problem is "completely eliminated."

For Reagan and Sakharov, who both have spent most of their lives advocating improvements in Soviet human rights but have taken very different approaches, the White House meeting was an unusual opportunity to exchange views. Sakharov, looking pleased, talked with reporters on the White House lawn after the meeting. He said the meeting had been "a great event," and added that the president "made a great personal impression on me."

During Sakharov's visit at the White House, the highlight of a whirlwind four-day visit here, he acknowledged the role the president has played in improving human rights in the Soviet Union, but indicated that Reagan's plans for the Strategic Defense Initiative are hampering U.S.-Soviet arms control talks.

Sakharov also appealed for help in a fight he is waging for the release of two Soviet political prisoners.

In Sakharov's fast-paced day, including a question-and-answer session at the Kennan Institute and a reception at the Library of Congress, he continued to express pessimism about the political situation in the Soviet Union and particularly the drive Soviet President Mikhail Gorbachev is waging for perestroika. Sakharov, a Nobel Peace Prize winner and a spokesman for Soviet reforms, is in the second week of his three-week trip to the United States, his first trip to the West.

Standing in the Oval Office next to Reagan, Sakharov raised the cases of Vasif Melyanov and Mikhail Kubokaka, two dissidents Sakharov says the West should be battling to get released from imprisonment in the Soviet Union.

Melyanov was jailed in 1980 for protesting Sakharov's exile that year to the closed Soviet city of Gorky and remains in exile two years after Sakharov's release. Kubokaka was imprisoned for refusing to testify against a foreign diplomat, Sakharov said.

The 20-minute exchange between Reagan and Sakharov was a mix of praise for the improvements in Soviet human rights in the past eight years and pledges to push for further changes. In 1980, Sakharov was exiled from Moscow for the outspoken stand he took on Soviet rights. Reagan took office the next year, and has spoken out ever since on behalf of Soviet dissidents.

Reagan was told by Sakharov that "individual political prisoners" remain in Soviet jails, but he also credited Gorbachev for having been "more cooperative than any Soviet leader before him." In the past two years, more than 150 political prisoners have been freed from Soviet jails but over 280 are still being held, according to Helsinki Watch, an international human-rights monitoring organization. Asked if he expected a total release for Soviet political detainees, Reagan said, "We can only wait and see."

In the wide-ranging discussions, Sakharov gave his assessment of the prospects for Gorbachev's drive for perestroika and voiced his skepticism of Reagan's plan to build a space shield against nuclear weapons.

Sakharov thanked Reagan for helping him and his wife, Yelena Bonner, White House spokesman Marlin Fitzwater said. "They had a very good discussion in which the president asked a number of questions," Fitzwater told reporters.

However, Fitzwater admitted that Sakharov had expressed his concerned about Reagan's plans to build a space shield against nuclear weapons, which Moscow has denounced as "destabilizing."

At a question-and-answer session, Sakharov reiterated the pessimistic view he has voiced towards the Soviet reform campaign since he arrived in the United States a week ago.

He complained of rising nationalist tendencies in the Soviet Union, of the remnants of repressive Soviet institutions created by Stalin, and of continued unlawful detentions in Soviet psychiatric hospitals, among other human rights abuses.

Charging Gorbachev with seeking democratic reforms through undemocratic means, Sakharov said, "there is no clear realization how this system should be reformed."

At the Kennan Institute session, Charles Z. Wick, director of the United States Information Agency, recounted that the Kremlin in May 1987 decided to cease jamming Voice of America radio broadcasts into the Soviet Union, and asked whether the VOA broadcasts were effective.

Before the period of glasnost, three years ago, VOA had been an important source of information for Soviet citizens, Sakharov said. But now information provided in the broadcasts and in the official Soviet media are virtually identical, he said, and listenership "has declined."