Secretary of State Cyrus R. Vance said yesterday the Carter administration will withdraw its offer of jet fighters for Israel if Congress blocks a related plan to sell planes to Egypt and Saudi Arabia.

"I think the only thing one could do under such circumstances would be to withdraw the package if all the pieces are not in it," Vance told a House subcommittee.

His words made explicit for the first time the threat at which administration officials have been hinting in the week since they announced a proposed $4.8 billion package of advanced jet sales for the Middle East.

The plan calls for selling 50 F5E fighters to Egypt, 60 F15 fighters to Saudi Arabia and 75 F16 fighter-bombers and 15 F15s to Israel.

All or parts of this sale can be blocked if both chambers of Congress vote against them. Until yesterday, the administration, although insisting that its proposal should be treated as a package, had avoided answering questions about whether it would sell planes only to Israel.

By putting the administration's position in unmistakable, all-or-nothing terms, Vance, in effect, warned pro-Israel members of Congress that, if they succeed in halting the sales to either or both of the Arab countries, Isreal will also lose out.

However, there were no immediate signs that the warning had the effect intended by the administration. Instead the initial reactions from both sides of Capitol Hill appeared to indicate either anger at an administration attempt to "dictate" to Congress or a feeling that the entire plane sale proposal should be set aside for the time being.

As one influential senator, Henry M. Jacskon (D. Wash.), said: "I don't believe Congress will accept an indivisible proposal. They can insist on a total package or none. But in the end, the House and Senate are still going to have to make their decisions on how they see the security needs of each of the three countries."

Sen. Jacob K. Javits (R. N. Y.), one of Israel's most prominent Senate supporters, said: "I would hope the administration will not take this position but will understand that the pertinent committees must first survey the total security situation in the area . . . I consider any declaration of withdrawal or nonwithdrawal as being premature."

More outspoken was Rep. Benjamin S. Rosenthal (D. N. Y.), who is expected to be among the leaders of moves in the House to block the sale to Saudi Arabia and possibly to Egypt.

He contended that the sales cannot legally be treated as a package because the different components involve financing, foreign aid and budgetary considerations that are covered by different laws.

"What Mr. Vance is saying is that it is the policy desire of the administration that they be treated as a package," Rosenthal said. "But there is no way to intimidate the Congress into making them a package."

While Vance's statement seemed to be pushing pro-Israeli members of there also were increasing signs on Capitol Hill that some members would prefer to see the entire arms package shelved.

That positon was expressed most vehemently by Rep. Clarence D. Long (D. Md.), chairman of the House foreign operations appropriations subcommittee, which heard Vance's testimony yesterday.

Long recalled that he had made 68 speeches on behalf of President Carter in last year's campaign, and said, "I wish now I had never made them at all. I am profoundly disappointed.

"There's no way you can convince me you can somehow get peace in a section of the world in which you are pumping vast arms," Long told Vance. "We have become the merchants of slaughter in this world."

Rep. Silvio O. Conte (R. Mass.), normally a staunch Israel supporter, revealed he had sent a letter to the 30 senators and 140 House members belonging to a bipartisan group called Members of Congress of Peace through Law.

In the letter, Conte noted fears that the plane sales could unsettle the Middle East peace negotiations, and called upon members of Congress to consider an "initiative" asking Carter to put a six-to eight-month moratorium on the deal.

Vance, who was asked repeatedly during has testimony why the sales couldn't be postponed, replied that all three countries had insisted on a decision now. The administration, he added, supports that view. And he noted that even if the orders are placed immediately, Israel and Saudi Arabia would not get the F15s until the summer of 1981.