Senior Jordanian officials, disappointed by what they view as a series of American failures in recent weeks to take action moving the Middle East peace ahead, have reduced their expectations of the role Washington is willing to play.

"It is you who is keeping us from moving," said one top official in an interview here.

He cited what Amman views as an American failure to push the Middle East question at the U.S.-Soviet Geneva summit, the congressional postponement of a new arms sale to Jordan and U.S. reluctance to back an international conference on the Middle East including the Soviet Union.

Western diplomats here familiar with King Hussein's views say that his disappointment with Washington and his continued need for broad Arab support in any negotiations with Israel are important factors in the Jordanian monarch's recent moves to sound out possibilities for support from Syria and the Soviet Union.

The peace process is now "spreading sideways rather than pressing forward because the Jordanians are trying to shore up their flanks," said one informed diplomat.

The king had hoped that strong U.S. backing would help assure him of what he considers essential support from relatively moderate Arab states in his search for peace with Israel.

"If you are taking a risk but the Americans are with you, it's far less likely that the Saudis, the Iraqis, the Tunisians, are going to turn on you," the diplomat said.

The postponement of the $1.9 billion weapons deal, which congressional pressure forced President Reagan to put off at least until March unless Jordan opens direct and "meaningful" talks with Israel, was the sharpest public blow.

"The congressional action has really hurt badly, it's cut the king deeply," the diplomat said. "He'll be looking elsewhere [for arms], but it's the political effects that have hurt him even more. This was supposed to be a symbol of American backing."

"The Arabs read it as an American president who couldn't buck the [Israeli] lobby . . . so you are a fool to expect Americans to protect your flank," this diplomat said.

The senior Jordanian officials, who asked not to be quoted by name for fear of making relations even worse, were nevertheless clear about the series of disappointments.

Interviewed soon after U.S. Middle East envoy Richard W. Murphy came here last week to brief the Jordanians on the summit, officials said they were told the peace process was mentioned only briefly by the two leaders at Geneva.

U.S. Secretary of State George P. Shultz "stated that the best solution was through direct negotiations" between Israel and Jordan, and Soviet Foreign Minister Eduard Shevardnadze "said, 'No, it was best through an international conference' and that was that," said one of the Jordanians.

The United States is opposed to an international conference for fear that the Soviets could veto any Israeli-Jordanian deal and the Syrians would gain even more influence in the region.

Israeli Prime Minister Shimon Peres has accepted the general idea of an international forum as a first step toward direct talks with a Jordanian-Palestinian delegation but also has made Soviet participation dependent upon Moscow's restoring diplomatic relations with Israel and allowing Soviet Jews to emigrate.

A Jordanian official said, "We have done all we think we can do." In the past three months, these sources said, Amman has improved relations with Syria and has had lengthy talks with Soviet officials on an internaional conference.

Along with Egypt, they said, they had also put considerable pressure on Palestine Liberation Organization Chairman Yasser Arafat to make explicit concessions demanded by the United States. One of these is the rejection of violence. Arafat, in a declaration in Cairo on Nov. 7, renounced violence outside what he called the "occupied territories."

But another PLO leader interviewed here, Khalil Wazir, said this territory still means all of Israel, rather than just the West Bank and Gaza Strip. He also acknowledged that violence by non-PLO Palestinians on the West Bank had increased and PLO control of operations had declined.

The Jordanians also have insisted that Arafat be ready to endorse U.N. Security Council Resolutions 242 and 338, effectively guaranteeing Israel's right to exist within secure borders.

Previously, this concession had been expected from Arafat in order to facilitate a U.S.-PLO dialogue as a first step in the peace process. But that step now appears from here to have been abandoned.

The Jordanians, the western diplomat added, "have reduced their concept of what the United States can do for them and have developed a more streamlined formula, compressing [the earlier plans] and focusing on an international conference" to be followed quickly by direct negotiations.

They want the Soviets in, he said, because they believe Moscow can exercise some influence over Syria. Syria, in turn, even if it just gives tacit support to a conference, can allow additional Arab support to Jordan.

"The help Jordan wants from the United States," the diplomat continued, "is to ease up on Soviet participation" in a conference. "What Jordan wants from Syria is tolerance, just let the conference happen . . . and see what happens."

"So," as one top Jordanian official put it, "we have been talking forcefully on three fronts, and the Americans did not bother to talk to anybody, neither the Russians, Syrians or Israelis. When Murphy comes here, every time he says 'We are pressed for time.' We say, 'All right, then do something.' "

"Frankly speaking," the Jordanian official continued, "Peres is moving better than the United States is moving. There seems to be no specific policy toward the Middle East" in the Reagan administration, he said.

The official said he believed "time is running out" for finding a settlement and that if Peres is replaced by the more conservative Likud government in Israel next October, as is now scheduled, then "it's finished."

"I believe something could be done between now and [Likud leader Yitzhak] Shamir's term," he said, "but it is you who is keeping us from moving. Accept the idea of an international conference," he added.

The Jordanians' disappointment about the arms deal and what they see as American lack of initiative has pushed Jordan toward Syria and the Soviet Union, the western diplomat said. "They've got to assure their Arab backing . . . . So now they are going to Syria and the Soviets to find out what their terms are," he said.

Jordanian and western sources here said Amman could look to Moscow for arms because the Soviets, like the Americans but unlike the British and French, provide credit. But Jordan, these officials said, vastly prefers U.S. weapons.

Jordan is getting some diplomatic support from Egypt.

When Arafat issued his "Cairo Declaration" on violence earlier this month in the presence of Egyptian President Hosni Mubarak, it was widely held that Mubarak had used the joint appearance with the PLO leader to restore some of his own tarnished image in the Arab world.

Jordanian officials said that there may have been an element of this, but the Egyptians "told Arafat, 'You have to do what the Jordanians asked you to do.' " Behind closed doors, the officials said, the Egyptians "were tough with him." They told him he had to accept the U.N. resolutions and that "there is no way for you to participate in any meaningful negotiations unless you agree with Jordan," according to the officials here.

Despite frictions and pressure from both Syria and Israel for an open break, Arafat and the king remain bound together in the peace process.

"The link with the PLO is absolutely critical to the king's Arab cover," concluded the western diplomat. With about 60 percent of Jordan's population made up of Palestinians, with hundreds of thousands more Palestinian workers with Jordanian passports spread throughout the Persian Gulf and more than a million Palestinians in Israel and the occupied territories, the Jordanians need Palestinian participation in peace talks.

The United States and Israel reject PLO participation, and the dispute about which Palestinians are to be represented remains unreconciled. No solution is in sight, diplomats here said, nor can one be finessed.