President Reagan has backed away for now from suggestions by conservatives in Congress and within the administration that he publicly denounce the Soviet Union for purported nuclear arms control violations, administration officials said yesterday.

Instead, one official said, the administration would first discuss privately with the Soviets any concerns about violations of nuclear arms limitation treaties "and give them an opportunity to satisfy them."

"If it involved a clear violation," the official said, the administration would communicate directly with Moscow through diplomatic channels. If there were "ambiguities," he said, it would be done through the U.S.-Soviet Standing Consultative Commission in Geneva, which was established by the SALT I treaty to handle allegations of violations by either side.

The president has reactivated an interagency verification committee, headed by national security affairs adviser William P. Clark, to review the alleged Soviet violations and recommend how they should be handled, officials said. The study would take time and involve consultations with both U.S. allies and the Soviets, they said.

According to administration officials, Reagan decided that making a public statement now, without first taking any complaints to the Soviets, would risk jeopardizing efforts to negotiate a new nuclear arms agreement.

The administration also will be "exceedingly careful" before it makes any accusations, one source said, because it did not want to be accused "of using Soviet violations to justify the new program" of U.S. nuclear missile development and deployment.

Officials said another reason for the Reagan administration's new caution was the difficulty of proving the Soviets had violated the SALT II treaty, which the United States has never ratified but which both sides say they are respecting.

A treaty provision some officials say the Soviets may have violated limits each nation to one new intercontinental ballistic missile. The Soviets appear to have tested two, according to these officials.

A senior Defense Department official said Monday that an earlier interagency review of Soviet treaty violations, chaired by the Department of State and delivered to the White House early this month, found "on close study that there appeared to have been skillful Soviet exploitation of loopholes" in SALT II and other treaties. Another official said the administration believes the Soviets are violating the treaty, but the evidence is "somewhat ambiguous."

Reagan's reactivation of the government's verification committee, with the implicit warning that it would call for a public focus on the violations if they continue, is seen by some in the administration as a veiled warning to the Soviets.

But this approach may not satisfy the demands of some conservatives in Congress and and the administration, who want Reagan to publicize the violations as an argument against the nuclear freeze movement and for his military buildup.

An administration official yesterday denounced what he called an "absolutely untrue" rumor among conservatives that Reagan was planning a speech to discuss Soviet treaty violations.

But a source close to some of the congressional conservatives pressuring the White House reiterated yesterday his belief that the president would speak out next week. "The White House has good intentions" about publicizing Soviet violations, he said, but "they are very nervous about doing it."

Reagan had told newsmen March 29 there were "increasingly serious grounds for question" about Soviet treaty compliance and "I may have more to say on this in the near future."

Reagan declined to answer yesterday when television reporters, at a photo ceremony, asked him whether the Soviets have violated the SALT treaties. But later an official quoted Reagan as having said, "When have they stopped?"