President Carter will meet separately with Egyptian President Anwar Sadat and Israeli Prime Minister Menachen Begin here next month in an effort to prod the Palestinian autonomy negotiations toward completion by their May 26 target date, the White House announced yesterday.

Press Secretary Jody Powell said the April meetings will "review the progress and pace" of the U.S.-mediated negotiations, which aim at creating a system of limited self-government for the Palestinian inhabitants of the Israeli-occupied West Bank and Gaza Strip territories.

Announcement of the visits came as a surprise and touched off speculation that the administration, which has suffered a recent string of foreign policy reverses, is concerned that the autonomy talks are moving too slowly to meet the May target and is seeking to avoid another setback by making an early start on breaking the deadlock.

Much of the speculation centered on whether Carter is trying to divert attention from the continued failure of efforts to free the American hostages in Iran and from the president's embarrassing disavowal of a U.S. vote for a United Nations resolution criticizing Israel.

Even viewed alone, the autonomy talks -- the current phase of the Camp David peace process that Carter counts as his greatest foreign policy achievement -- are of vital importance to the president's image.

In fact, there was widespread suspicion in political circles yesterday that announcement of the visits was timed to help Carter in New York's Democratic primary next Tuesday. His challenger for the presidential nomination, Sen. Edward M. Kennedy of Massachusetts, has been exploiting the U.N. vote on Israel in an effort to woo New York's large bloc of Jewish voters.

However, a White House official denied suggestions that the visits were a hastily devised device to help Carter politically or bolster his credibility in the foreign policy arena.

The official, who declined to be identified, said the idea of asking Begin and Sadat to come to Washington has been under discussion within the administration since Feb. 18, when Carter broached the subject at his weekly Friday breakfast with top foreign policy advisers.

The matter was discussed on two or three occasions after Feb. 18, the official added, and a decision to go ahead was made at the breakfast meeting last Friday. The president telephoned Begin and Sadat on Tuesday, the official said, and both agreed immediately to come.

In stressing that the idea was Carter's "personal initiative," the official said the meetings here are intended as a "reaffirmation" of the commitment by both the president and the United States "to sustaining the Camp David process" that produced the peace treaty signed by Egypt and Israel a year ago.

Despite this contention that the initiative had been in the works for some time, other administration officials involved in the autonomy, talks were saying as recently as late February that Carter was unenthusiastic about becoming involved in anything that might look like a "summit conference" and that no plans for top-level meetings were being considered.

However, that situation began to change after the March 1 U.N. vote on a resolution criticizing Israel's policy of establishing settlements in the occupied territories. Carter's disavowal of the U.S. vote on March 3 is believed to have been prompted, in part, by fears that Israel would scuttle the autonomy talks in retaliation.

The president's U-turn on the U.N. resolution caused severe strains in U.S. relations with both Israel and the Arab world and left the administration's Mideast policy in disarray. In the aftermath, some key policymakers are known to have advocated trying to recoup by giving a high priority to completing the autonomy talks on schedule, and yesterday's announcement appeared to indicate that the president has taken that advice.

The White House official said Carter would meet Sadat and Begin separately because he feels that a one-on-one exchange with each would be more productive in terms of isolating the problems in the Palestinian talks. The meetings here, the official stressed, are not intended as a substitute for the three-cornered negotiations going on in the Middle East.

Carter's special negotiator in those talks, Sol M. Linowitz, will leave for Israel and Egypt on Friday for the next round of negotiations, and White Ouse officials said he also would work out the scheduling of the Begin and Sadat trips.

Linowitz, who talked briefly with reporters at the White House yesterday, said there were no plans for converting the separate visits into a new three-way summit similar to the 1978 meeting at Camp David. But he added that nothing is being ruled out and that a get-together involving all three leaders is "conceivable."

The autonomy talks, which flow from the Egyptian-Israeli peace treaty, are charged with finding a formula for electing a Palestinian entity to exercise limited self-government in the occupied territories for five years and defining what powers that entity will have.

So far, limited progress has been made in defining the election process and in settling on some of the less controversial powers that the elected body will be given. The exact state of the talks has been kept secret at Egypt's insistence, but it is known that none of the major issues has been resolved.

These involve such sensitive questions as control over land, security and limited water supplies, the voting rights of residents in formerly Arab-controlled East Jerusalem, and the future of Jewish settlements in the occupied territories.

The Begin government has been especially intractable about insisting on continued Israeli security control of the territories, on the right of Jews to settle there, and on not allowing any status for the territories that might lead to their transformation into an independent Palestinian state.

That, in turn, has caused the rest of the Arab world to regard the negotiations as a pretext for "creeping Israeli annexation" of the territories and has frustrated U.S. efforts to draw such key pro-western Arab states as Saudi Arabia and Jordan into the peace process.

Some of Washington's European allies, notably France and Britain, lately have been talking about new initiatives that would be more acceptable to the Arab states by trying to draw the Palestine Liberation Organization into the process.

While the Carter administration clearly is unhappy about the stirrings in Europe, the White House official denied that they were a factor in the efforts to quicken the pace of the autonomy talks.