Lebanon's US-backed ruling coalition challenged their Hizbullah-led rivals Saturday, demanding that top-level talks in Qatar on ending Lebanon's 18-month old political crisis - which turned violent a week ago - also tackle the issue of Hizbullah's weapons. However, the Hizbullah side insisted the group's arsenal was not to be touched, according to Lebanese media reports on the first day of the negotiations in the Qatari capital. The Doha-hosted meeting between the Lebanese factions on forming a national unity government and electing a president was agreed under an Arab League-mediated deal to end Lebanon's worst violence since the 1975-1990 civil war. Following Arab mediation, the feuding sides flew to Qatar on Friday, after agreeing that the talks would lead to the election of compromise candidate Army chief Gen. Michel Suleiman as Lebanese president. Lebanon's official National News Agency said the talks became tense when parliament majority leader Saad Hariri, a Sunni, and hard-line pro-government Christian politician Samir Geagea brought up the issue of Hizbullah's weapons. The private LBC Television said the feuding sides engaged in "heated discussions" over the subject, which took up most of the morning session. The TV said pro-government leaders stressed that the sectarian fighting, which erupted in Beirut and other areas last week, must not be allowed to recur. This indicated that Prime Minister Fuad Saniora's side was looking for guarantees in Qatar that Hizbullah won't again take to the streets as it did when it overrun Muslim Sunni west Beirut neighborhoods last week. Geagea had warned Hizbullah that Doha talks would fail if the Shi'ite Islamist group sticks to keeping its weapons. "We can no longer accept Hizbullah as it is," he told the Qatari Al-Jazeera TV. Telecommunications Minister Marwan Hamadeh told The Associated Press from Qatar that he expected "three critical days" before any sort of compromise is reached, but that the Doha talks would include "Hizbullah's use of its weapons to achieve internal political aims." The eruption last week was triggered by government measures to rein in Hizbullah, whose fighters then responded by taking up arms. The clashes left 67 people dead and over 200 wounded. The violence eventually forced the government to revoke the measures, giving Hizbullah an upper hand in its standoff with the government. The standoff has paralyzed Lebanon politically, and left it without a president since pro-Syrian Emile Lahoud's term ended last November. It started in Nov. 2006, when six Hizbullah ministers and their allies resigned from the Cabinet because it would not give them veto power on government decisions. Lawmaker Mohammed Raad, who heads Hizbullah's delegation in Qatar, defended the group's keeping its arsenal, saying the weapons were meant to fight against Israel and "must not be touched," according to LBC. Subsequently, Qatari host Prime Minister Sheik Hamad bin Jassem al-Thani asked the two sides to stick for now to discussions on a national unity government. According to NNA, they set up a four-party committee to draft a new election law. "It's not easy," Amin Gemayel, a pro-government politician and former president, was quoted by NNA as saying in Doha. Still, Saniora struck an upbeat note, saying Saturday's session showed "all parties are eager to reach an understanding that will lead to the beginning of a solution to this crisis," the private Voice of Lebanon Radio reported. Washington and Saniora's faction have accused Iran and Syria of seeking to undermine the Lebanese government and Middle East stability, while Hizbullah accuses the prime minister and his allies in the anti-Syrian coalition of being America's servants. In Egypt Saturday as part of his Middle East tour, US President George W. Bush said that Lebanon's latest turmoil - perceived by the US and many in the Sunni Arab world as a demonstration of Shi'ite-controlled Iran's quest for more regional influence - was another dominant topic in his talks with Palestinian Authority President Mahmoud Abbas. Bush said he and Abbas agreed on their concern about "radical elements undermining" Saniora's government. "This is a defining moment," Bush said. "It is a moment that requires us to stand strongly with the Saniora government and to support the Saniora government." Bush had planned to meet with Saniora Sunday in Egypt, but the session was canceled. Talks in Qatar are the first time top leaders from the Lebanese sides came face-to-face in the 18 months crisis.