CNN — The aim is ambitious, but the expectations are low.
As top diplomats gathered in Switzerland for international talks aimed at ending Syria's protracted civil war, U.N. Secretary-General Ban Ki-moon urged the opposing sides in the conflict to seize the opportunity for peace.
"After nearly three painful years of conflict and suffering in Syria, today is a day of fragile but real hope," he said at the start of the conference in the Swiss town of Montreux.
But the obstacles to finding a solution to the conflict -- which threatens to destabilize the Middle East -- quickly became apparent at the conference, which was beset by squabbles before it even began.
In his opening statement, U.S. Secretary of State John Kerry said there is "no way" that Syrian President Bashar al-Assad will be part of a transitional government in the war-ravaged country.
Al-Assad, whose forces are accused of widespread abuses, can't "regain the legitimacy to govern," Kerry said, drawing a sharp retort from Syrian Foreign Minister Walid al-Moallem.
"No one, Mr. Kerry, no one can grant or withdraw the legitimacy of the President other than the Syrians themselves," al-Moallem said. "This is their right and duty."
The Syrian official also clashed with Ban, who tried to cut him off several times. But al-Moallem wouldn't stop talking.
"You live in New York. I live in Syria," al-Moallem told the U.N. chief.
Ban, Kerry and al-Moallem joined diplomats from Russia and other world powers near Lake Geneva to discuss how to address a conflict that has killed more than 100,000 people and shows no signs of ending anytime soon.
Representatives of al-Assad's regime and the Syrian opposition are also attending the conference, bringing to the negotiating table bitter foes who have been engaged in a complex, bloody fight since 2011.
The war has become increasingly sectarian, drawing in Syria's regional neighbors and forcing out more than 2 million refugees, many of them children.
Analysts say the prospects of reaching any solution to the conflict at the talks are dim, but there are hopes that progress could be made on improving the situation for the most vulnerable victims of the civil war.
Dozens of Syrian government supporters demonstrated outside the conference in Geneva, chanting in support of al-Assad.
The preliminary international session started Wednesday in Montreux, but the direct talks between the Syrian government and opposition delegations aren't slated to begin until Friday in Geneva.
But the president of the Syrian National Coalition, the main Syrian opposition movement, said the first day of talks has already been productive.
"We thank Secretary Kerry for his strong comments in support of the Syrian people's struggle for freedom & dignity @StateDept #Geneva2," Ahmad Jarba said on Twitter.
"We are now inviting the Assad delegation to participate in a free Syria. Find courage and join us now, in freedom and peace in a new Syria."
The opposition and Iran
Several high-profile complications emerged even before the talks started, setting the tone for a challenging conference.
The Syrian National Coalition didn't decide until Saturday whether it would attend. The SNC finally agreed in a vote that exposed deep divisions within its ranks.
One of the groups in the coalition blasted it for agreeing to participate in the talks, accusing it of heading to Geneva with "a folder of concessions and withdrawals."
And furor has surrounded the embarrassing public announcements by Ban, who invited -- and then disinvited -- Iran to the conference. Iran is a key supporter of al-Assad's regime.
The controversy over Iran, which is believed to provide military and intelligence support to Syrian government forces, threatened to derail the talks at one point.
Russian Foreign Minister Sergey Lavrov chided the United Nations on Tuesday for its abrupt U-turn on Iran, following pressure from the main Syrian opposition group and the United States.
Iran had already announced that it wouldn't be attending the peace conference because it would not tolerate any preconditions for joining the talks -- including acceptance of the framework laid out in a previous conference that foresees a transitional government.
Lavrov called Ban's reversal a mistake, but "not a catastrophe," adding that Russia and others will push for balanced talks between those representing al-Assad and the rebels. Moscow has been a longtime ally of the Syrian government.
He pointed out that Kerry, among others, recognized publicly that Iran is an important player in resolving the Syrian conflict.
Russian Prime Minister Dmitry Medvedev told CNN's Christiane Amanpour that the talks cannot be taken seriously without Iran involved.
"The thing that has happened with the withdrawal of the invitation to Iran, I believe that's unacceptable," Medvedev said in an exclusive interview to air Wednesday on CNN's "Amanpour." "Can someone think the Syrian problem can be seriously discussed without the Iranian factor and their account of it?"
Besides the United States and Russia, the other permanent members of the U.N. Security Council -- Britain, France and China -- are attending the conference, along with more than 25 other countries. Representatives of the Arab League, the Organization of Islamic Cooperation and the European Union will also take part.
The aim of the talks in Switzerland is to set up a transitional government to help end the violence that has wracked the country.
The first round of peace talks -- held in 2012 and known as Geneva I -- called for a transitional government and eventual free elections as part of a political settlement to end the war.
But the different sides in the conflict are at bitter odds.
"We have little hope that the Assad regime would come with good will to these negotiations," coalition spokesman Louay Safi told CNN ahead of the talks. Al-Assad's government "is not interested in a political solution, and they will continue to kill the Syrian people."
Al-Assad, whose forces have regained momentum against a now-fractured opposition, has said he's not looking at the talks as a way to transition out of power.
Syrian officials have talked instead about the conference as a way to arrange a cease-fire in Syria's largest city, Aleppo, with hopes of extending that truce to other parts of the country.
Al-Assad has called for the conference to include a focus on fighting "terrorism," his government's term for rebel forces.
In a meeting with Syria's delegates to the talks, al-Assad directed them to preserve their nation's sovereignty by "preventing and rejecting any foreign interference no matter its form and context," the state-run Syrian Arab News Agency reported Monday.
Al-Assad also said no political solution could be reached without the agreement of the Syrian people and "first and foremost the complete cessation of terrorism" and its support by other countries, the news agency said.
Western intelligence officials believe Iran has provided fighters, intelligence and communications to support al-Assad.
In addition, fighters from the Iran-backed Lebanese Shiite militia Hezbollah have seen combat in Syria on the side of the government.
Most outside support for rebel forces has come from the Gulf monarchies of Saudi Arabia and Qatar.
In a sign of the Syrian regime's disdain for the Arab League -- which suspended the regime's membership after its crackdown in 2011 -- Syrian state-run TV labeled the League's secretary-general with a scornful caption Wednesday: "Nabil Al-Arabi is speaking on behalf of the Saudi-Qatari petro-dollar that dictates him and the Arab League."
U.S. aid has been limited largely to nonlethal assistance such as communications gear and medical equipment, and American officials have struggled with how to back opposition groups without providing weapons to those linked to Islamic militants.
CNN's Holly Yan, Laura Smith-Spark, Ben Brumfield, Matt Smith, Chelsea J. Carter, Shirzad Bozorgmehr, Christine Theodorou, Samira Said and Nick Paton Walsh contributed to this report.