Beirut (AP): Leaders of Lebanon's U.S.-backed government and the Hezbollah-led opposition met behind closed doors in Qatar on Saturday for the highest-level talks so far in the 18-month-long political crisis in Lebanon.

The Doha-hosted meeting on forming a national unity government and electing a president was agreed under a deal, mediated by the Arab League, to end Lebanon's worst violence since the 1975-1990 civil war.

But the government side raised the stakes on the Doha talks Saturday, insisting they must tackle the issue of the weapons used by the Iranian-backed militant Hezbollah, considered a terrorist group by the United States.

Telecommunications Minister Marwan Hamadeh told The Associated Press from Qatar that the talks would _ along with the unity government and a new election law _ discuss ``Hezbollah's use of its weapons to achieve internal political aims'' in the wake of recent violence.

Hamadeh said he expects ``three critical days'' before the sides reach any sort of compromise on the standoff that has pushed Lebanon to the brink of an all-out conflict.

Lebanon's crisis has paralyzed the country and left it without a president since pro-Syrian President Emile Lahoud's term ended last November.

A week ago, the standoff dissolved into violence when the government passed measures to rein in Hezbollah, whose fighters then responded by overrunning neighborhoods of west Beirut in clashes that left 67 people dead and over 200 wounded.

The violence eventually forced the government to revoke the measures, making it a major victory for Hezbollah and indicating that the militant group had gained the upper hand in the power struggle.

The feuding Lebanese factions arrived in Qatar Friday, where Emir Sheikh Hamad Bin Khalifa Al-Thani welcomed them saying he hoped the Lebanese would come to an agreement and prevent further clashes in their country.

Hardline Christian pro-government politician Samir Geagea warned Hezbollah that the talks would fail if the group sticks to keeping its arsenal in defiance of state authority. ``We can no longer accept Hezbollah as it is,'' Geagea told the Qatari Al-Jazeera TV.

The opposition side, represented by pro-Syrian Parliament Speaker Nabih Berri and three Hezbollah lawmakers, had no immediate comments.

Under the Arab League deal, the talks in Doha would lead to the election of compromise candidate Army chief Gen. Michel Suleiman as Lebanese president.

Lebanon's crisis, sparked by the resignation from Cabinet of six Hezbollah ministers in November 2006, has wider regional implications.

Washington and Saniora's faction have accused Iran and Syria of seeking to undermine the government and Middle East stability, while Hezbollah accuses the prime minister and his allies in the anti-Syrian coalition of toeing the pro-American line.

U.S. President George W. Bush and Saudi King Abdullah shared their concerns over the Lebanon violence during a meeting Friday in Riyadh, Bush's national security adviser Stephen Hadley told reporters.

The two were concerned the Lebanon events would ``embolden Iran,'' Hadley said, adding that the U.S. and Saudi Arabia both condemn ``what Hezbollah did in bringing pressure on the duly elected government of Lebanon.''