The Carter administration stepped up public expression on the Polish crisis yesterday in measured, incremental fashion, and the Polish ambassador offered official thanks for the U.S. show of rhetorical restraint.

The administration's statement, issued in the name of Secretary of State Edmund S. Muskie, repeated the view that "internal problems in Poland are for the Polish people and the Polish authorities to resolve." This clearly implied, though it cautiously refrained from saying so, that the current problems in Poland are not for the Soviet Union or any other outside power to resolve.

Muskie's statement, which was approved at a policymaking breakfast of President Carter and his senior foreign policy advisers yesterday, also expressed concern about the arrest of Polish dissidents. "We hope they will be released soon," the statement said.

Nearly everything that was said in Muskie's two-paragraph statement had been previously said at one point or another in the sparse administration comment on the Polish strikes. By stringing together all the sentences and putting them in the name of the secretary of state, the administration gave them slightly greater visibility without going beyond the previously established policy.

Carter, in an interview published in yesterday's editions of The Boston Globe, said he had decided "as a matter of national policy to make minimal comments about Poland during this time of instability there." To express U.S. views more bluntly "would be destabilizing and might work counter to our purposes," Carter said.

Carter added that "we hope, and I might say we expect, that there will be no further Soviet involvement in polish affairs because of this series of strikes and demands for more political and economic improvements. But I can't predict that for sure."

Late yesterday, Polish Ambassador to the United States Romuald Spasowski came to the State Department on instructions from the Warsaw government to explain the official Polish point of view and express appreciation for the U.S. stand on the situation.

Asked if it would help for the United States to be more assertive, Spasowski said, "No. What is most important is to create quiet conditions in which people can find a solution to the problems."

The ambassador said the Polish government is determined not to use force "if at all possible." He also said he did not think there is much danger of Soviet intervention "because the Polish govenment is determined to find a peaceful solution."

Deputy Secretary of State Warren Christopher, who met with Spasowski for 25 minutes, was quoted by a spokesman as being "reassured" to hear that the Polish government intends to settle the problems peacefully.

Christopher also was quoted as raising a human rights issue regarding treatment of dissidents. The State Department spokesman said Spasowski replied that Poland is conscious of its human rights obligations but that he can give no further assurances in view of the "difficult situation" at home.