Iranian Foreign Minister Ibrahim Yazdi today introduced a conciliatory note into increasingly venomous criticism of the United States since a Senate resolution condemning summary executions in Iran.

"Our stand against the U.S. Senate cannot harm our relations with America," Yazdi said at a news conference, adding: "Breaking off relations with America depends on America."

Yazdi's remarks did little to disguise the tension in U.S.-Iranian relations since the revolutionary forces of Ayatollah Ruhollah Khomeini took over Iran last Februrary. But they demonstrated that at least some parts of Prime Minister Mehdi Bazargan's government want to avoid letting the dispute over Khomeini's Islamic firing squads develop into a break in relations.

Yazdi also seemed to be making a particular effort to distinguish between the Senate and President Carter's over all foreign policy. Before joining Khomeini in Paris last winter and coming with him to Iran, Yazdi spent a number of years in the United States and presumably has a better knowledge of the U.S. political system than most Iranians.

"American executive power is separate from its legislative power," he said. "Therefore, the Senate resolution does not necessarily represent America's foreign policy."

For the same reason, however, it was unclear how much weight Yazdi carries against the scathing attack on the United States made by Khomeininpersonally, in which he said the U.S. government is like a "wounded snake" upset over the shah's downfall. Because of his American cnnection, Yazdi already has had to defend himself against leftist accusations that he is everything from a CIA agent to a U.S. government plant.

In Washington, the State Department took a notably restrained position on the Iranian statements over the weekend. Spokesman Ken Brown appealed for Iran to accept the new U.S. ambassador, Walter L. Culter, "at an early date" on grounds that the envoy may be able to "heop in straightening out the misunderstanding between our two countries."

The spokesman expressed "concern" about verbal attacks against Sen. Jacob Javits (R-N.Y.), author of the Senate resolution. On the subject of the executions, Brown repeated the U.S. disagreement on human rights grounds to trials and executions without Western-style due process of llaw.

The Senate resolution expressed "abhorrence" at the summary trials in which more than 200 have been executed. It was cited as an example of interference in Iranian affairs in the announcement yesterday that Iran had asked Washington to postpone Cutler's arrival until the "political atmosphere" is cleared up.

Yazdi said that on May 13 the Foreign Ministry received a note from Secretary of State Cyrus Vance in which Vance said "he wanted to broaden relations with our country and help Iran in the economic, social cultural and other fields, including military aid."

A reply containing a protest over the Senate resolution and the request for Cutler to remain in Washington for the time being was handed to the U.S. Embassy in Tehran today. U.S. diplomatic sources said it confirmed what they had been told orally yesterday.

Yazdi rejected the Senate's reference to statements by a prominent member of the Iranian clergy. Ayatollah Sadegh Khalkhali, that supported the idea of assassinating the shah and members of his family. Khalkhali has been identified as the head of the revolutionary tribunals.

But Yazdi emphasized that Khalkhali "is not even a member of the courts." He went on: "So we are very sorry the Senate issued a declaration based on an unconfirmed piece of news."

Asked whether the shah had indeed been sentenced to death, as stated by Khalkhali, Yazdi replied, "You must ask that of the courts."

He also rejected any criticism of the trials and executions that have taken place.

"There has been a revolution in this country and it is up to the Iranian people to try the criminals according to revolutionary standards," he said "This is an internal matter."