Ahead of an election that could oust the US-backed Beirut government, Secretary of State Hillary Clinton said Sunday that Washington supported "voices of moderation" and would never make a deal with Syria that "sells out" Lebanon's interests. The June 7 vote could boost the Iranian-backed Hizbullah and its allies, possibly paving the way for renewed Syrian influence over Lebanon. "The people of Lebanon must be able to choose their own representatives in open and fair elections without the specter of violence or intimidation and free of outside interference," Clinton told a news conference after meeting with Lebanese President Michel Suleiman. "Beyond the elections, we will continue to support the voices of moderation in Lebanon and the responsible institutions of the Lebanese state they are working hard to build. Our ongoing support for the Lebanese armed forces remains a pillar of our bilateral cooperation," she added. Syria dominated Lebanon for nearly three decades before it was forced to withdraw its tens of thousands of troops four years ago in the wake of the assassination of former prime minister Rafik Hariri. There have been concerns among anti-Syrian factions in the pro-US parliamentary majority that the Obama administration's talks with Syria could weaken American support for Lebanon. In a possible sign of a new diplomatic openness between the US and Syria, American officials noted that Clinton's plane flew to Lebanon from Kuwait directly through Syrian airspace, instead of bypassing it as such flights usually do. Clinton said she delivered a letter from Obama to Suleiman expressing strong support for a free, sovereign and independent Lebanon. She said US attempts to engage Syria and Iran are not being done at the expense of that support. "There is nothing that we would do in any way that would undermine Lebanon's sovereignty," Clinton said. "I want to assure any Lebanese citizen that the United States will never make any deal with Syria that sells out Lebanon and the Lebanese people. You have been through too much and it is only right that you are given a chance to make your own decisions," Clinton said. "It's a complicated neighborhood you live in and you have the right to your own future," she added. Hizbullah spokesman Ibrahim Mussawi said Clinton's visit could have a negative impact on the pro-US factions in the country. Speaking on the group's Al-Manar TV after Clinton arrived, Mussawi said it was too early to tell whether the Obama administration has reassessed its policy. But, he added, American "interference in the past was never positive." He also criticized what he termed a "double standard and deception," when the US calls for Islamic factions to participate in elections and then refuses to accept the results if they win. Clinton first trip to one of the most volatile countries in the Middle East lasted a little less than three hours. She would not speculate on the results of the election and what the US would do if Hizbullah wins, stressing a free and fair elections. US officials have said they would review aid to Lebanon, including military assistance, depending on the composition of the new government. The United States has provided $1 billion in aid since 2006, including $410 million in security assistance to the military and the police. Although the US and Israel regard Hizbullah as a terrorist organization, the Shi'ite terror group shares power in Lebanon's current government and along with its allies, has veto power on major decisions. A strong showing by Hizbullah would further boost Iranian and Syrian influence in the Mideast and could harm Arab-Israeli peace efforts. While urging free and fair elections, the Obama administration is treading carefully. The Bush administration encouraged the Palestinian legislative elections in 2006 and then saw Hamas win handily and badly damage efforts to broker an Israeli-Palestinian peace deal. Reflecting that concern, Clinton met during her brief stay with just one senior official, Suleiman. US officials say her meeting with Suleiman only is because the US doesn't want to be seen as taking sides in the elections. Suleiman is considered a consensus leader and neutral in the political struggle. Even if it wins, Hizbullah cannot rule alone because of Lebanon's complex, sectarian power-sharing system in which the major of the 18 sects must be represented in parliament and the Cabinet. Hizbullah leader Hassan Nasrallah says the group knows that trying to dominate Lebanon's politics would destabilize the country. In the past four years, Lebanon has nearly tumbled into a repeat of the 1975-90 civil war as the pro-Syrian and pro-US camps struggled for the upper hand. Hizbullah has taken the strategy of a low-key election campaign with a moderate message, aiming to show that a victory by its coalition should not scare anyone. Nasrallah has even said that if the coalition wins, it would invite its opponents to join in a national unity government to ensure stability. Before leaving Lebanon, Clinton stopped at Hariri's grave to lay a wreath. She renewed US support for an international tribunal based in the Netherlands to try his killers. "There needs to be an absolute end to an era of impunity for political assassinations in Lebanon," Clinton said.