Jordanian Prime Minister Mudar Badran made a surprise visit to Damascus yesterday for talks with Syrian President Hafez Assad.

Syria's state-controlled press, meanwhile, stepped up its denunciation of Egyptian President Anwar Sadat's Christmas summit with Israeli Prime Minister Menahem Begin and called for the Egyptian leader's ouster.

No details of Badran's talks with Assad were disclosed, but Jordan has sought to prevent a widening of the Arab split that followed Sadat's historic visit to Jerusalem last month.

Jordanian King Hussein is to meet with President Carter Saturday during his stop in Tehran. Iran, on the presidential world tour. There has been wide speculation that Jordan will join the currently recessed talks among Israel, Egypt, the United States and the United Nations.

The Damascus daily Tishrin, controlled by the Syrian government, said Sadat should step down because his policy "has reached a dead end now that he has failed to fufill the simplest of his promises."

"Begin did not make any concessions to Sadat that approached" Sadat's concession in agreeing to visit Jerusalem, the paper said.

The only important result of the summit was that Egypt and Israel succeeded in alienating the Palestine Liberation Organization from the peace process, it added.

Damascus' state radio broadcast from an anti-Sadat rally at the town of Hama, 125 miles to the north, with the crowd clapping and the announcer shouting, "We will not kneel down. We will not surrender."

Syria's chief of staff, Gen. Hikmat Shehabi, held talks in Moscow with Soviet Defense Minister Marshal Dmitry Ustinov. Again, no details were disclosed, although the Soviet news agency Tass described the talks as "warm, friendly." Moscow is a major supplier of arms to Syria.

PLO leader Yasser Arafat arrived in Belgrade for a working visit, the Yugoslav news agency Tanjug reported. The PLO's news agency said Monday that the organization was taking responsibility for the assassination of an Arab official on the Israeli-occupied West Bank of the Jordan River who they said had cooperated with the Israelis.

Both the PLO and Syria have denounced Begin's proposal for limited self-rule on the West Bank, and challenged Sadat's authority even to discuss the issue.

In the critical area of the Persian Gulf, according to sources in Bahrain quoted by Reuter, these nations whose oil wealth helps sustain Sadat privately voiced disappointment in the results of the summit with Begin.

The gulf area countries, led by Saudi Arabia, were hoping that Israel would show more flexibility, the sources said.

Sadat's stress on the need for a comprehensive peace settlement and Begin's reiteration of the same theme at their joint press conference was the one bright point in Monday's news from Ismailia, they added.