Discussions on peace in Syria began Wednesday with bickering between U.S. and Syrian diplomats over President Bashar Assad and whether he could rule Syria. Top diplomats gathering in Switzerland for international talks aimed at ending Syria's civil war of nearly three years heard U.N. Secretary-General Ban Ki-moon urge all sides to grab the chance for peace, CNN reported. "After nearly three painful years of conflict and suffering in Syria, today is a day of fragile but real hope," he said, kicking off the conference in the Swiss town of Montreux. However, in his opening statement, U.S. Secretary of State John Kerry said there is "no way" Assad will be part of a transitional government in the war-torn country. Assad, whose forces are accused of a host of brutalities, can't "regain the legitimacy to govern," Kerry said. "The right to lead a country does not come from torture," Kerry said. "The only thing standing in the way is the stubborn clinging to power of one man." Russian Foreign Minister Sergei V. Lavrov disputed U.S. insistence that Assad not be part of a possible transitional administration, arguing that the conference must "refrain from any attempt to predetermine the outcome of the process," the New York Times reported. Lavrov also argued Iran, which supports the Assad regime as does Russia, should be at the conference. The United States opposed allowing Iran to participate until it publicly endorses the conference's mandate and successfully pressed the United Nations to withdraw its invitation to the Islamic republic. Syrian Foreign Minister Walid al-Muallem, who also clashed with Ban, responded, "No one, Mr. Kerry, no one can grant or withdraw the legitimacy of the president other than the Syrians themselves. This is their right and duty." Speaking for more than an hour instead of his allotted 7 minutes, Muallem also accused Arab nations of financing terrorism and conspiring to destroy his country, the Times said. "They have used their petrodollars to buy weapons," he said, "and to flood the international media with lies." When Syrian National Coalition President Ahmad al-Jarba spoke, he denounced the Assad government and Iran, which has sent arms and troops to support Assad. "We want to be sure we have A Syrian partner in this room." Jarba said. "Do we have such a partner?" He also said the opposition would never accept Assad being part of a transitional administration. Diplomats were meeting in Switzerland to discuss how to address a conflict the United Nations estimates killed more than 100,000 people and displaced millions since the conflict began in March 2011. Representatives of Assad's government and the Syrian opposition are also attending the conference. The international session began Wednesday in Montreux but direct talks between the Syrian government and opposition delegations won't begin until Friday in Geneva. The official objective of the peace talks, known as Geneva II, is to establish a process to create a transitional government with full executive powers that would run the country until elections can be held, likely excluding Assad. This was the objective worked out at an international conference on the Syria conflict, known as Geneva I, held in Geneva in June 2012. Syria has said its intention for the talks is to fight "terrorism," the term the regime uses to describe the opposition. Assad has also said he would not step down or share power with the opposition. Analysts say prospects of reaching any solution are slim, but hold out hope progress could be made to improve the situation for the most vulnerable, CNN said. Before the conference, President Obama and Russian President Vladimir Putin spoke by phone about the Syrian peace conference on the eve of its Wednesday start, both countries said. "The conversation was businesslike and constructive in manner," the Kremlin said in a statement. The White House didn't characterize the call, which also included other issues. "They discussed the situation in Syria, including preparations for the Geneva II conference and the ongoing international program to remove and destroy Syria's chemical weapons," a statement issued by the White House said.