Syria promised Arab leaders at an annual summit on Saturday to cooperate in ending a political crisis in Lebanon, and regional power Saudi Arabia said it saw Damascus as part of the solution.
The conciliatory language on Lebanon offered some relief from the tensions that have built up during preparations for the two-day meeting, which Lebanon and key pro-U.S. Arab leaders are skipping in protest against Syria's Lebanon policy.
The Beirut government is boycotting the summit while Saudi Arabia, Egypt and Jordan have sent low-level delegations.
Eleven heads of state from the Arab League's 22 members were present at the opening, less than normal for an Arab summit, reflecting a suspicion that through its local allies Syria has obstructed the election of a new Lebanese president
The conflict over Lebanon is part of the wider struggle for regional influence between the United States and Syria's ally Iran.
Assad dismissed accusations that his country was behind the deadlock in Lebanon, which has not had a president since November because the government and the Syrian-backed opposition cannot agree on the composition of a new cabinet.
He also rejected criticism of Syria's conduct, saying: "On the contrary, the pressures which have been put on Syria for more than a year, and increasingly for the last several months, have been to have Syria intervene in Lebanese internal affairs."
At a news conference in Riyadh, Saudi Foreign Minister Prince Saud al-Faisal denied that Arab countries were trying to isolate Syria over the Lebanese crisis.
"On the contrary, Syria is one of the important countries in the region and, naturally, Arab countries are keen to have Syria as part of common Arab action," he said.
Arab foreign ministers in January approved an outline of a deal for Lebanon, including the election of army chief Michel Suleiman as the new president, a choice approved by both sides.
But the Beirut and the opposition differ over the interpretation of other aspects of the Arab plan, especially whether the opposition should have veto power over cabinet decisions.
Prince Saud added: "We hope the summit will be able to resolve the Lebanon crisis based on the initiative of the Arab League ... especially since the summit is held in Damascus, from which we are still awaiting a positive move on the Lebanese scene to implement the initiative..."
Arab League chief Amr Moussa told the summit he would resume his efforts to end the Lebanese deadlock.
Assad opened the summit with an uncharacteristically short speech devoid of provocative or confrontational language. He did not mention the absence of Lebanon or the low level of representation by the some Arab governments.
Syria says the United States campaigned to dissuade Arab leaders from attending. Washington faults Syria for its policies in Lebanon and for supporting Palestinian guerrilla groups.
An international investigation team has also implicated Syrian officials in the assassination of former Lebanese prime minister Rafiq al-Hariri, one of the reasons for the crisis in Lebanon. Syria says it had nothing to do with the killing.
The Arab leaders will repeat the Arab initiative of 2002, which offers Israel peace and normal relations with all Arab countries in return for withdrawal from all territory captured in the Middle East war of 1967.
Israeli governments have rejected or ignored the initiative, which would require dismantling settlements which house hundreds of thousands of Jews in East Jerusalem and the West Bank.
Libyan leader Muammar Gaddafi, the longest-serving Arab head of state after 38 years in power, said the Arabs should improve relations with Iran, rather than provoke it.
"You have no escape from Iran. It is a neighbour and Muslim brother and it is not in your interest to be its enemy," Gaddafi told the summit.