The United States and the Soviet Union expressed the desire today to reach new agreements at the November summit of their leaders even as they stressed their continuing strong differences over human rights and arms control.

New Soviet Foreign Minister Eduard Shevardnadze, making his international debut at ceremonies marking the 10th anniversay of the Helinski accords, gave a speech markedly free of the tough rhetoric for which his predecessor, Andrei Gromyko, was known. He stressed the Soviet offer yesterday of a new five-month moratorium on all nuclear testing as an effort to help establish conditions making possible a new arms control agreement.

Shevardnadze said the summit should help ease international tension and emphasized that the Soviet Union was in favor of reaching agreement "on an honest and equal basis."

Secretary of State George P. Shultz said the United States was "ready and willing to seize the opportunity" provided by the summit and called upon both countries to begin "the patient, serious work" necessary to reach agreements.

Shultz delivered an otherwise hard-hitting attack on the human rights record of the Soviet Union, charging that it had failed to keep "the most important promises" of the 1975 Agreement on Security and Cooperation in Europe.

Shultz devoted the bulk of his speech to detailing a long record of Soviet violations of political and religious freedoms, listing by name at least two dozen persons as victims of arbitrary arrest and imprisonment.

Both speakers expressed disillusionment with the results of a decade of work trying to implement the Helsinki accords but reaffirmed their strong commitment to the process.

"Our country is prepared both now and in the future to implement in full the obligations it assumed in Helsinki," the Soviet foreign minister said.

Shevardnadze and other Soviet spokesmen at the conference skirted the issue of human rights violations, even dropping the recent Soviet tack of accusing western countries of violating their citizens' "social and economic rights."

Asked at a press conference if the Soviet Union intended to use the occasion to free some well-known political dissidents, Soviet Deputy Foreign Minister Victor Komplektov replied, "I'm not discussing this matter with you."

"There are different ways to commemorate anniversaries," he said. "We are commemorating it by putting forth our specific proposals."

Shevardnadze dismissed the West's emphasis on the human rights issue as simply a question "directly related to the sphere of ideology where the socialist states and the capitalist world hold opposite positions."

"A line should be carefully drawn between ideological differences and interstate relations," he added.

Shevardnadze blamed the lack of progress in implementing the Helsinki accords mainly on the U.S. military buildup and the Reagan administration's pursuit of its Strategic Defense Initiative, which he said were "fraught with serious negative implications for both European and world security."

The foreign minister's appearance was the main attraction at the start of a three-day session attended by 35 foreign ministers from Europe, the United States and Canada.

Shevardnadze, 57, a member of the Politburo, gave a bland performance as he read his eight-page speech in Russian with a strong Georgian accent, rarely lifting his eyes from the text or injecting any emotion into his delivery.

As a member of Soviet leader Mikhail Gorbachev's new team, the former party boss of the mountainous Caucasian republic of Georgia is reputed to be forceful and dynamic. But these characteristics were not in evidence today.

Both the United States and the Soviet Union indicated before coming here that they regarded a scheduled three-hour meeting between Shultz and Shevardnadze Wednesday as perhaps the most important event of the gathering, since it will be their first meeting and will mark the formal start of preparations for the Nov. 19-20 summit in Geneva between Communist Party General Secretary Gorbachev and President Reagan.

At the heavily attended Soviet press conference, held while Shultz was speaking, Komplektov dismissed "as nothing new at all" the U.S. offer yesterday to the Soviet Union to send a team of observers to monitor the next American underground nuclear test.

The Soviet official said Reagan had already made the same proposal at the U.N. General Assembly last September and Moscow had said then the objective was to stop, not to observe, all nuclear testing.

However, a senior State Department official here said the latest offer was not the same, since there was no demand for U.S. teams to go to the Soviet Union to monitor tests there and it was made "without preconditions."

The official said the United States had not yet received an official Soviet response to the U.S. proposal.

Eastern and western speakers' concentration on the failings of the Helsinki accords to date offered few deviations from either side's well-known positions on such issues as arms control and human rights.

One representative of those affected by the latter theme, Avital Scharansky, the wife of imprisoned Soviet dissident Anatoly Scharansky, was refused access to the sprawling lakeside Finlandia Hall.