President Carter last night expressed "bitter disappointment" at the failure of the United Nations-led negotiations to obtain release of the American hostages in Iran, but gave no hint that he is shifting his policy toward confrontation with that country.

In his first news conference since a series of setbacks in foreign affairs, Carter passed up the opportunity to signal an end to the policy of patience and restraint that he has adopted during secret international maneuvering to win the Americans' freedom.

Carter blamed the failure of the hostage negotiations on the inability of the Iranian government of President Abol Hassan Bani-sadr to honor its promises with regard to the work of the U.N. commission. Yet he did not seem to hold Bani-Sadr and his aides personally at fault, saying that "They obviously do not have the authority to speak and carry out their own commitment," before the election of an Iranian parliament.

That election, Carter noted, is now under way. He expressed hope, but no certainty, that the voting will provide Iran's government with sufficient power to effect the hostages' release.

Despite "constant negotiations" and attempts at "continuing communications" with the leaders of Iran, Carter said in discussing the hostages, "I don't know when they will be released."

Carter did not say what commitments had been unfulfilled by the Iranian authorities. Official sources here and at the United Nations have said that Iran clearly had promised to permit the U.N. commission to see each of the 50 Americans at the occupied American Embassy and to transfer the control of the captive Americans from student radicals to a government authority.

The president began his news conference -- the first in four weeks -- with a lengthy restatement of his proposals to balance the federal budget as a means of combatting the nation's high rate of inflation. But many of the questions from reporters dealt with the problems and setbacks of his foreign policy.

Carter described as "an honest breakdown in communications between me and the United Nations" the recent U.S. flip-flop on a resolution criticizing Isreali settlements in occupied territory. The United States voted for the resolution in the U.N. Security Council two weeks ago today, but two days after the vote Carter disavowed it as a mistake.

"I don't think anyone in my administration doubts I'm the one who sets our policy," the president replied to a question about who was in charge. He went out of his way to praise Secretary of State Cyrus R. Vance, who had taken full responsibility for the embarrassing and diplomatically costly reversal.

Carter reassured Israel that U.S. policy in the Arab-Israeli dispute is unchanged and that the future of Jewish settlements on the West Bank of the Jordan River is to be determined in negotiations and not through U.N. resolutions.

Faced with a question that implied criticism of Israel's recent confiscation of land for housing on the outskirts of Jerusalem, Carter avoided passing judgment on the Israeli decision, which officially has been deplored by the State Department. He said merely that the matter was not covered by the Camp David accords.

The president said he had disavowed the U.N. resolution because it was not in accord with his policies or with commitments he had made to Israeli Prime Minister Menachem Begin during the Mideast peace talks.

Carter said that although the United States opposed Israeli settlements in occupied territory, he had agreed not to call for dismantling of existing settlements while the peace negotiations continue. He added without giving details, that the U.N. resolution violated an Israeli-Egyptian-U.S. agreement that Jerusalem would be undivided but accessible to worship by all faiths.

Carter also said that he intends to honor the provisions of the Strategic Arms Limitation Treaty (SALT-II) -- whose ratification by the Senate is being held in abeyance -- as long as the Soviet Union also honors its provisions and as long as U.S. observance is in the national interest. He said he will consult with congressional leaders on continued compliance.

Regarding ratification of the treaty, Carter promised continuing consultations with Senate leaders but did not express optimism that the pact soon will be brought to the Senate floor for consideration.

"It is obvious we would not be successful at this time" in getting the treaty ratified, Carter admitted.