President Carter welcomed Egyptian and Israeli leaders to the White House yeaterday to mark the first anniversary of the Camp David accords and promised to take a personal hand in Middle East peace talks if they again encounter major stumbling blocks.

"In the future, if there are obstacles of a seemingly insurmountable nature, I'd be deeply committed to becoming involved," Carter said at the brief ceremony in the White House rose garden.

He was responding to Israeli Foreign Minister Moshe Dayan, who recalled how Carter's flying trip to the Middle East last March paved the way for signing the Egyptian-Israeli peace treaty. Dayan added, "If necessary, we might ask you to extend your guiding hand once again."

Although the tone of the meeting was strongly upbeat, both Dayan and Egyptian Vice President Hosni Mubarak stressed that furthering the peace process will require resolution of serious problems in the new round of negotiations between the two countries.

These talks, being conducted under U.S. mediation, are aimed at reaching agreement on some system of self-government for the Palestinian inhabitants of the Israeli-occupied West Bank and Gaza Strip territories.

A new note of tension was introduced into the situation Sunday when the Israeli cabinet decided to allow Israelis to buy private land in the occupied territories. Egypt attacked the move sharply yesterday as an attempt "to usurp the rights of the Palestinian people in their country and on their land."

Murbarak, in his White House statement, did not refer specifically to the Israeli decision. But he underscored the Egyptian attitude by referring to the Palestinian question "as the heart and core of the entire conflict" and added:

"We should refrain from any rash act that would jeopardize the prospects for peace at this crucial stage. Acts of defiance and negativism should be avoided. This policy of confrontation and 'fait accompli' is contrary to the spirit of Camp David."

Dayan, in his remarks, zeroed in on another problem that has been causing unhappiness on the Israeli side of the bargaining table -- a dispute with the United States about creating a permanent peacekeeping force to supervise Israeli withdrawal from the Sinai peninsula.

The United Nations Emergency Force in the Sinai orginally had been expected to handle that task. But the threat of a veto by the Soviet Union in the U.N. Security Council blocked renewal of UNEF's mandate earlier this summer.

Israel insists that under the Camp David agreements the United States is obligated to set up a substitute force. But the proposal advanced by the Carter administration -- using U.N. truce supervisors -- has been rejected by Israel as unacceptable because the personnel would be inadequately armed and under the control of U.N. Secretary General Kurt Waldheim.

Egypt and Israel have reached a stopgap agreement for the job to be handled temporarily by mixed Egyptian-Israeli patrols. But Israel still is demanding a more permanent arrangement, and, as Dayan noted yesterday, he and Secretary of State Cyrus R. Vance will begin talks today on how to resolve the peace force dispute.

Still, even these shadows lingering over the peace process were unable to dissipate the festive air of the ceremony, in which Carter reviewed the events of the past year and concluded: "It's obvious that both countries, both peoples, both leaders are determined this process will be successful."

Carter revealed that he spoke by telephone yesterday with Egyptian President Anwar Sadat and Israeli Prime Minister Menachem Begin. The two leaders also sent messages reaffirming their commitment to peaceful relations and lauding Carter's role in what Begin's message called "a turning point in the annals of the Middle East."

That the administration is keenly aware of the problems still awaiting resolution was underscored in a speech made last night by Carter's national security affairs adviser, Zbigniew Brzezinski, to a meeting of the World Jewish Congress in New York.

Although Brzezinski billed his address as a "personal vision of peace," White House sources said it had been reviewed by Vance and Carter's special mideast ambassador, Robert S. Strauss. They said it represented a top-level consensus of the issues the administration believes must be addressed in the ongoing peace negotiations.

Essentially, Brzezinski made three main points -- the need for Israel and Egypt to think in terms of the security and stability of the Middle East as a whole, the need to start looking for nontraditional solutions to the Palestinian question and the need to continue the talks on West Bank and Gaza Strip autonomy even if the Palestinians refuse to participate.