President Carter said last night that, because of a foulup, the United States incorrectly voted Saturday for a United Nations resolution calling on Israel to dismantle its settlements in occupied Arab territories.

The error, he said, centered not on the resolution's main thrust regarding the settlements but on its references to the status of Jerusalem.

In a statement issued last night by the White House, the president said the United States should have abstained during the U.N. Security Council vote, but did not because of a mistake in transmitting his instructions clearly to U.N. Ambassador Donald F. McHenry.

The surprising public admission of an administration foulup on a highly sensitive foreign policy matter, while it left many questions unanswered, was certain to add to the confusion in the wake of the U.N. vote, which deeply angered Israeli officials and was earlier condemned by Carter's Democratic presidential rival, Sen. Edward M. Kennedy (D-Mass.).

Before the president issued his statement, adminstration officials said yesterday that he and Secretary of State Cyrus R. Vance had approved the U.S. position. The United States abstained on two similar votes in the Security Council last year.

The United States has long opposed the establishment of Israeli settlements in the occupied territories of the West Bank and Gaza. But it has taken a much more ambivalent position toward East Jerusalem, asserting that the city should be considered indivisible.

The U.N. resolution makes several references to East Jerusalem, some of which tend to equate that area with the West Bank and Gaza Strip. Overlooking this, according to adminstration officials, was the [WORD ILLEGIBLE] of the error that led to last night's unusual statement by the president.

Officials said that McHenry was not at fault, and it was understood that the foulup occurred in the State Department in transmitting Carter's instructions to the U.S. delegation at the United Nations.

In his statement last night, Carter sought to calm the angry Israeli reaction with a reiteration of U.S. policy on Jerusalem and the overall U.S. committment to Israel's security.

He also said that the resolution's call for the dismantling of the Israeli settlements was impractical, an argument McHenry also made before voting for the resolution. According to adminstration officials. McHenry was instructed to vote for the resolution even if it called for dismantling the settlements. But McHenry was supposed to abstain if the resolution referred to Jerusalem. The part of the instructions that apparently were mishandled by the State Department.

Asserting that the U.S. vote in the Security Council does not represent a change in American policy toward the Israeli settlements in the West Ban and Gaza or the status of Jerusalem, Carter said the resolution's called for dismantling the settlements "was neither proper nor practical."

He added:

"We believe that the future disposition of existing settlements must be determined during the current autonomy negotiations [the ongoing Mideast peace talks].

"As to Jerusalem, we strongly believe that Jerusalem should be undivided with free access to the holy places for all faiths, and that its status should be determined in the negotiations for a comprehensive peace settlement.

"The United States' vote in the United Nations was approved with the understanding that all references to Jerusalem would be deleted. The failure to communicate this clearly resulted in a vote in favor of the resolution, rather than in a abstention."

Carter concluded his statement by saying that in the Mideast peace negotiations "the United States will neither support nor accept any position that might jeopardize Israel's vital security interests. Our commitment to Israel's security and well-being remains unqualified and unshakable."

In the wake of the Security Council vote, stories began circulating here yesterday that the U.S. decision to support the resolution had caused deep divisions within the adminstration. According to these sources, the State Department and Carter's special Mideast mediator, Sol M. Linowitz, had favored a U.S. abstention but had been overruled after McHenry appealed directly to Carter for instructions to vote in favor.

Reliable sources said privately that the U.S. decision, made after several days of wavering between an abstention and a "yes" vote, was attributable to Vance and Carter directly and did not reflect an intervention by McHenry or anyone else.

In the end, the sources added, McHenry was told specifically to vote for the resolution by Vance in a telephone conversation on Saturday morning shortly before the Security Council vote.

At not time in the days preceding the vote did McHenry meet or speak directly with Carter, the sources insisted. Instead, they said, the basic decisions were made by Vance in consultation with the president.

Senior adminstration officials dealing with the Middle East have become increasingly concerned in recent weeks about the possibility that the Begin government's settlements policy could jeopardize the Israeli-Egyptian negotiations on creating a self-governing system for the Palestinian inhabitants of the West Bank and Gaza.

This U.S. anxiety became greatly accelerated after the Begin cabinet agreed in principle to permit Jewish settlement in the center of the exclusively Arab West Bank city of Hebron.

The U.S. aim was to shape the resolution in ways that would clearly censure Israeli settlements policy but that would avoid other language criticizing Israeli policy on other matters or implying any threat to Israel's security or right to exist.

According, McHenry was instructed to try and negotiate with other council members language that would meet his requirements. In the negotiations that reached a high pitch early last week, the first draft resolutions contained language or features that the United States considered unacceptable, and the adminstration made clear it could not vote for them.

Objections to a U.S. vote in favor of any resolution came from White House officials concerned about the Jewish vote and from Linowitz, who reportedly said he did not object in principle to censuring Israeli settlements policy but who feared that the timing could affect adversely the autonomy talks.

The sources said Israeli officials in Washington and New York were told during the week that the United States was undecided how it would vote, and they conceded that this wavering might have caused some misunderstanding. But, the sources added, McHenry met with Israeli U.N. Ambassador Yehuda Blum on Friday and informed him it was likely the United States would vote for the resolution.