President Reagan and Soviet leader Mikhail S. Gorbachev held a second round of talks at the Kremlin Monday amid a sudden air of optimism that agreement could be reached on two secondary arms-control pacts that had appeared stalled in pre-summit maneuvering.

Reagan coupled his summit talks with two separate events intended to dramatize his concern about religious freedom and human rights. He paid a visit to Moscow's oldest monastery, where he was greeted by the pealing of church bells. Reagan also invited Soviet dissidents and refuseniks to visit with him at the U.S. Embassy residence where he is staying.Reagan's second day in Moscow began with a meeting with Gorbachev in St. Catherine's Hall behind the brick walls of the Kremlin enclave.

Commenting on Soviet willingness to allow his meeting with dissidents and refuseniks, Reagan said, "They did that for me so that I'd feel at home."

He added, "Every once in a while I am meeting some rather disagreeable people at home," without explaining the reference.

As the red hammer and sickle fluttered alongside the American Stars and Stripes on major thoroughfares, Reagan and Gorbachev put arms control differences at the top of Monday's agenda.

Neither side expected enough progress to produce a treaty to achieve a goal both leaders have deep cuts in the superpowers' arsenals of nuclear bombers and missiles. Verification issues appeared insurmountable.

A U.S. official said Monday that chances were improving for signing an agreement providing advance notification of nuclear missile tests and another agreement establishing procedures for monitoring experimental nuclear explosions at Semipalatinsk in the Soviet Union and the Department of Energy's Nevada test site.

As recently as Saturday, Assistant Secretary of State Rozanne L. Ridgway said "it is not going to be possible to reach agreement" on the notification pact because the Soviets were trying to expand it beyond what was acceptable to the United States.

Officials also had said it appeared that technical issues would block final agreement at the summit on the nuclear monitoring agreement.

Reagan and Gorbachev fielded a half-dozen questions at the start of their second Moscow meeting.

Gorbachev said he had the impression neither side had "a very good idea" about human rights situation in the other's country. He said that was why he had proposed to Reagan that the U.S. and Soviet legislatures set up joint seminar groups to explore the issue.

Reagan, meanwhile, said he was aware of "big improvements" in human rights in the Soviet Union.

Reagan, the first American president to visit the Soviet Union since 1974 and only the fourth president here ever, arrived Sunday afternoon to an honor ceremony at Vnukovo Airport, where a Soviet military band flawlessly played the U.S. national anthem.

The Soviet and American national emblems were posted on every light pole along Reagan's motorcade route. Friendly crowds gathered in clusters outside the city for a glimpse of the American leader, and by the time Reagan reached the downtown, people were standing four and five deep and lined the balconies of apartment buildings.

On an unannounced walking excursion at the Soviet version of a pedestrian mall, Reagan and his wife Nancy were rewarded by smiles, cheers and applause from a big crowd. The upbeat scene was marred by roughneck tactics of KGB security agents, who pushed, punched and shoved through the dense crowd to clear a path for the Reagans.

The first couple seemed stunned at the tumultuous scene and appeared at times to be jostled themselves. Absent the heavy-handed tactics, the episode was reminiscent of Gorbachev's crowd-pleasing, handshaking stop on a busy Washington street corner during the summit last December.