In a policy shift apparently aimed at improving relations with Israel and avoiding problems with China, the United States will allow the sale of up to 60 Israeli Kfir jets to Taiwan, Carter administration officials said yesterday.

U.S. approval, required because the planes are equipped with American made engines, was conveyed by Vice President Mondale to Israeli Prime Minister Menachem Begin at a meeting Sunday in Jerusalem, the officials said.

The U.S. action reverses a prohibition imposed by the Ford administration three years ago on the sale of Kfirs to the Republic of China on Taiwan. By removing its veto, Washington appears to be trying simultaneously to ease some sensitive policy problems in the Middle East and Far East.

Permitting the plane sale would help the United States meet its commitment to assist Taiwan in defending itself from attack. At the same time, it could help avoid normal relations with China by interposing Israel rather than the United States as a direct supplier of arms to Taiwan.

In the Middle East the reversal appears to be a gesture aimed at easing strained U.S. Israele relations. If the sale to Taiwan goes through, it would give the financially hard-pressed Israeli aircraft industry an estimated $500 million.

U.S. sources also noted that the gesture comes at a time when the United States is pressing Israel to send its foreign minister to London later this month for a meeting with his Egyptian counterpart and Secretary of State Cyrus R.Vance. in a new attempt to revive the bogged-down Mideast peace talks.

The United States is in process of relaying a new Egyptian plan for the future status of the Israeli - occupied West Bank and Gaza Strip Department spokesman Hodding Carter III said yesterday that the United States hopes the Egyptian plan, taken in conjunction with an earlier Israel proposal affecting the occupied territories, will provide new momentum for the talks that broke down in Jerusalem Jan.18.

Although the arrangements are still being negotiated, the London meeting is expected to take place July 18 and 19. In London, spokesman Carter said, the United States hopes the two sides will discuss and probe each other's plans to find possible areas of agreement that could provide the basis for further negotiations.

The United States, he stressed, does not favor one plan over the other and has no proposals of its own "to thump on the table." Vance, he said would be there "as a party on good terms with both sides" who will try to act as a "facilitator or bridge" to help the Is raelis and Egyptians find their way around any impasses in the talks.

Carter sidestepped questions about whether there was a connection between the Mideast talks and the U.S. reversal on the Kfir sales. Instead, while confirming that the United States would "look favorably" on such a sale, Carter insisted that he did not know whether the Taiwan government even wants to buy jet fighters from Israel.

He also denied that the proposed Israeli sale means the United States has decided to deny Taiwan's request to buy U.S.F4 phantom jets. A decision on the sale of F4s to Taiwan has not yet been made, Carter said.

The Nationalist Chinese government on Taiwan has been seeking for some time to bolster its air force with more modern planes. However, its original negotiations with Israel for the Kfir, a fighter-bomber based on the French Mirage design, were blocked by the Ford administration also vetoed Israeli plans to sell two dozen of the planes to Ecuador.

Washington holds this right of veto over Israeli sales of the Kfir to other countries because the plane's engine is manufactured by the General Electric Co. in the United States.

After its negotiations with Israel were blocked, Taiwan turned to the United States and began trying to strike a deal for U.S.F4s. But while the United States has reaffirmed its commitment to help Taiwan defend itself, it also has signed the Shanghai Communique concurring in Peking's claim that Taiwan is a territorial part of mainland China.

Some U.S. experts said privately that the Kfir deal, if it can be brought off, will give Washington a chance to balance these two positions.For one thing, it would substitute Israel as Taiwan's plane supplier, thereby defeclting some of the anger that Peking might otherwise direct at Washington.

It also would give the Taiwan government a plane, the Kfir, capable of defending the Taiwan Straits but lacking the range to attack mainland China. By cont rast, the F4 has a much greater range and could be used to make bombing strikes deep inside mainland China.