Israel today officially rejected the U.N. Security Council resolution condeming its bombing of an Iraqi nuclear reactor, accusing the world organization of double standards and severely criticizing the United States for helping in a "grave wrong."

"The government of Israel condemns the Security Council's resolution of condemnation and categorically rejects it," declared a resolution unanimously adopted by the Cabinet.

Prime Minister Menachem Begin, reading the communique to reporters after the Cabinet session, said, "In deep sorrow, we note that the United States, our friend and ally, as stated by its ambassador to the United Nations, gave hand to the grave wrong done to Israel."

In what appeared to betray irritation at private negotiations between the United States and Iraq to reach agreement on the compromise resolution condemning the June 7 bombing raid near Baghdad, the Israeli resolution added:

"The United States even conducted talks with Iraq in order to formulate a resolution agreed beforehand between the two of them. Israel, which believes in the justice of its cause, will continue to defend its citizens and to prevent its enemies from producing weapons of mass destruction aimed at its population, with all the means at its disposal. This is Isreal's sacred duty."

The sharpness of the Israeli of the United States came as something of a surprise. When it became clear last week that the Reagan administration was backing a U.N. censure, Begin seemed to temper his reaction in an apparent attempt to minimize the differences between Israel and the United States in the final days of a heated campaign for national elections June 30.

Since Begin has been capitalizing in his campaign on the sympathetic attitude of the Reagan administration toward Israel, it would not have been politically advantageous to spotlight worsening relations between the two countries, even though governments here normally gain in public support when they come under pressure from abroad.

At the same time, however, Begin has been firm in defending what he declares is Israel's right to conduct such preemptive military operations, even at the risk of further straining relations with the United States.

For example, Begin last night told an election rally that he would rather have a U.N. resolution of condemnation without an Iraqi nuclear reactor than an Iraqi reactor without a U.N. resolution.

Meanwhile, relations between Israel and Egypt also appear to have taken a turn for the worse. The Egyptian ambassador to Israel, Saad Mortada, said there may be a provisional slowdown in normalization as a result of the attack on Iraq.

Mortada did not specify what steps would be taken by Egypt, but two Egyptian delegations due here this week to discuss trade relations and a summer youth exchange program canceled their visits without explanation. On Friday, Israeli Foreign Ministry and Egyptian Embassy officials denied that the normalization process underwritten by the Egyptian-Israeli peace treaty would be disrupted as a result of the reactor raid.

Egyptian diplomats here stressed that even with a slowdown the substance of the peach treaty will not be affected. They noted that an Egyptian delegation will meet with the Israelis this week to discuss final details of Israel's final withdrawal from the occupied Sinai Peninsula next April.