BEIRUT (AFP) – UN Secretary General Ban Ki-moon arrived in Beirut on Thursday and immediately called for dialogue and compromise to end Lebanon’s most serious crisis since the end of the civil war in 1990.

The UN chief, currently on his first official tour of the Middle East, will hold talks on Friday with Prime Minister Fuad Siniora and parliament speaker Nabih Berri, officials said.

His talks are expected to cover the political crisis in Lebanon as well as plans for the creation of an international court over the 2005 murder of former premier Rafiq Hariri and the status of the UN investigation into the killing.

Flying in from an Arab League summit in Riyadh, Ban told reporters at Beirut airport: "I came at an important time where all are trying to pressure for peace and security. The challenge is particularly serious in Lebanon."

He echoed comments he had made earlier at the summit, where the presence of two rival delegations representing Lebanon underscored the division paralysing the country.

"We hope that dialogue and reconciliation will prevail. I hope that the efforts of Lebanese and Arab mediators will prevail. All will lose from an escalation. Dialogue and compromise are the only ways toward national unity," Ban said.

On Saturday, he is expected to travel to southern Lebanon to visit the UN peacekeeping force monitoring a ceasefire that ended last year’s war between Israel and the Lebanese Shiite Muslim movement Hezbollah.

In an address to the Arab summit on Wednesday, Ban warned that the political stalemate in Lebanon "threatens to undermine one of the region’s most vibrant societies."

"The situation in Lebanon must be another of our priorities.

"I am pleased that the cessation of hostilities is holding," he said, referring to the fragile UN-brokered truce last August which ended the devastating 34-day war between Israel and Hezbollah.

But Ban added: "I regret, however, that Lebanon continues to go through internal political turmoil."

"Differences should be resolved through dialogue and genuine efforts at national reconciliation and consensus."

Ban also told the Arab leaders that Siniora had "displayed impressive leadership under difficult circumstances, and I urge you to support his democratically elected government."

His remark triggered a grimace from Siniora’s rival, the pro-Syrian President Emile Lahoud, who is heading one of the two separate delegations.

Lahoud and the Damascus-backed opposition consider Siniora’s Western-backed government "illegitimate" after all Shiite Muslim ministers resigned last November.

The country has since been paralysed as the opposition insists on an enlarged cabinet in which it would wield a veto — a demand rejected by the ruling majority.

The government accuses the opposition of acting under Syrian pressure to paralyse political institutions and block the creation of an international tribunal to try suspects in Hariri murder, widely blamed on Damascus.

His killing triggered domestic and international protests which forced Damascus to end 29 years of military presence and political domination of its neighbour in April 2005 Syria denies any involvement in Hariri’s death.

The UN team probing the assassination has also been investigating a series of attacks that targeted Lebanese figures hostile to Syria’s role in the country.