The Reagan administration, eager to revive the stalled Mideast peace process and overcome congressional resistance to a billion-dollar arms sale to Jordan, now believes that any break in the impasse must come during a visit to the United States next week by King Hussein, U.S. officials said yesterday.

Hussein is scheduled to address the U.N. General Assembly on Sept. 27 and meet with President Reagan at the White House on Sept. 30. U.S. officials expect the occasions to clarify how far the king is willing to go to satisfy congressional demands that there be no arms sale until Jordan begins direct peace talks with Israel.

"It is clear that under present circumstances we cannot make a successful case to Congress for selling arms to Jordan unless we can point to some kind of success in the peace process," said one State Department official, who asked not to be identified.

"We have to find a way to move the two in tandem," he added. "Whether we can do that will depend on what Hussein says publicly at the U.N. and privately at the White House. He knows what the situation is. The question is whether he will offer opportunities for follow-up that will make the hope of peace talks a more realizable goal than has been the case until now."

Last weekend it was revealed that the administration, eager to avoid a congressional fight over a proposed sale of F15 fighter planes to Saudi Arabia, had agreed to a Saudi decision to buy more than $3 billion worth of British planes.

The Israeli government, which was observing the Jewish New Year Monday and yesterday, has not indicated what it intends to do in reaction to the proposed sale, although it issued a protest statement Sunday.

However, U.S. officials expect Israel to argue that the Saudi sale will mean a major shift in the Mideast arms balance that should be offset with the sale of more U.S. fighters to the Jewish state -- perhaps even the same F15s that the Saudis had wanted.

In contrast to U.S. acquiescence in the Saudi-British deal, however, U.S. officials said the administration is determined to press ahead -- probably before the end of September -- with a large arms package for Jordan, including F16 or F20 fighter planes.

According to the officials, the administration feels a sense of obligation to Hussein for past friendship toward the United States and wants to encourage him to begin peace talks. Nevertheless, officials acknowledge that the extent to which the administration is now depending on Hussein to shed his caution is symptomatic of how much the administration's hopes for success in the Mideast have faded since the king's last visit in May.

However, the officials said that if the administration's commitment to Jordan is to be more than an expenditure of precious political capital in a losing cause, Hussein must modify his present conditions for movement on the peace process.

Specifically, these involve his demands that the United States meet with a Jordanian-Palestinian delegation without Arab guarantees that such a meeting will lead to talks with Israel, and his insistence that peace negotiations be part of an international conference that would include the Soviet Union.

Hussein and Egyptian President Hosni Mubarak, who will meet Reagan next Monday, will be told that these conditions are unacceptable, officials said.

The two will also be told "that the administration will keep its promise and go forward with proposing the arms sale. But if Hussein wants to keep it from being killed in Congress, he has to demonstrate that there is life in the peace process. He has to decide whether it's a risk worth taking," one official added.

Reagan's willingness to commit his prestige to what is likely to be a losing battle is being cited as evidence of how far the administration is prepared to go on Hussein's behalf. U.S. officials added that the decision to abort the parallel sale of F15s to Saudi Arabia was prompted, in part, by a feeling that the administration should conserve its political clout to fight for the Jordanian package.