UNITED NATIONS —As Syria ramps up an effort to break itself out of diplomatic isolation, top Lebanese politicians are seeking a Security Council directive to end Syria’s influence on Lebanese politics.

An American businessman of Syrian descent, who still has close ties to Damascus, visited Jerusalem yesterday in an attempt to renew diplomatic negotiations between Israel and Syria. Syria has hinted recently that it is ready to launch a new round of diplomatic talks with Israel. Yesterday, Ibrahim Suleiman told Knesset members in Jerusalem that Syria “will not start a war” with Israel. “Syria right now is ready to speak peace,” Mr. Suleiman told reporters in Jerusalem afterward. “I challenged the Israeli government to answer President Bashar’s call for peace and sit down together.”

But while some Israeli parliamentarians have agreed that the time is ripe to start negotiations, government officials dismissed the overtures, saying that rather than a sign that substantial agreements are at hand, Damascus uses a fruitless diplomatic process to fend off international pressure. Some suggested the overture was an attempt to fend off threats of an international trial in Lebanon, where Syrian officials could be linked to the assassination of a former Lebanese prime minister, Rafik Hariri. The international tribunal proposed by the United Nations to try suspects in the 2005 Beirut car bombing that killed Hariri is meeting tough resistance from Syria’s allies in Lebanon, who have blocked a parliamentary vote necessary for final approval of the international judicial body.

On Tuesday, Prime Minister Siniora asked Secretary-General Ban to end the parliamentary impasse in a letter that followed a similar letter last week, which was signed by a majority of parliament members. In both cases, Mr. Ban was asked to intervene and call on the Security Council to establish the tribunal despite the divisions among Lebanon’s politicians.

“I urge you to put this matter before the esteemed members of the Security Council to examine alternative ways and means that will ensure the establishment, without delay, of the Special Tribunal for Lebanon, which is essential for the safeguarding of liberties and deterring further political assassinations,” Mr. Siniora wrote to Mr. Ban in a letter dated April 10.

Mr. Ban, who intends to visit Syria in two weeks, said yesterday he is “very much concerned by the lack of progress on this issue.” Council diplomats said they expected Mr. Ban to conduct more diplomatic negotiations before the council starts negotiating a resolution to establish the tribunal.

Before Mr. Ban’s upcoming trip to Damascus, senior U.N. diplomats are expected to travel to Lebanon and Syria to attempt to convince officials there to accept the tribunals, according to a U.N. diplomat who has asked for anonymity.

Mr. Ban’s upcoming one-day visit to Syria will come less than a month after an earlier trip to the region and on the heels of a much-discussed visit to Damascus by the U.S. speaker of the House, Rep. Nancy Pelosi.

Israeli Foreign Ministry officials yesterday declined an invitation to meet Mr. Suleiman. “He is much closer to the top echelons of government than we thought earlier,” a Jerusalem official said, asking for anonymity. But he added that no pending talks are expected.

Last week, Prime Minister Olmert said talks with Syria would start only when the country ends its support for terrorists in the Palestinian Arab territories, Lebanon, and Iraq. Top government officials have also told press outlets that members of the Bush administration have asked Israeli counterparts to avoid entering into serious negotiations with Syria.