MONTREUX, Switzerland -- Furiously divided from the start, representatives of Syrian President Bashar Assad and the rebellion against him threatened Wednesday to collapse a peace conference intended to lead them out of civil war.
Assad's future in the country devastated by three years of bloodshed was at the heart of the sparring, which took place against a pristine Alpine backdrop as Syrian forces and rebel fighters clashed across a wide area from Aleppo and Idlib in the north to Daraa in the south.
U.S. and U.N. officials said merely getting the two sides in the same room was something of a victory, but U.N. chief Ban Ki-moon's claim that the discussions were "harmonious and constructive" was at odds with the testy exchange when he tried to get the podium from Syrian Foreign Minister Walid Moallem.
"You live in New York. I live in Syria," Moallem angrily told Ban. "I have the right to give the Syrian version here in this forum. After three years of suffering, this is my right."
With little common ground, the two sides were to meet separately Thursday with a U.N. negotiator, Lakhdar Brahimi, who said he still did not know if they were ready to sit at the same table when talks begin in earnest Friday. But, Brahimi said, both sides had shown some willingness to bend on local cease-fires and delivery of humanitarian aid, and Russian Foreign Minister Sergey Lavrov said they were also working on possible terms for a prisoner exchange.
The Western-backed opposition said Assad's departure was their starting point, echoing the position laid out by U.S. Secretary of State John Kerry.
"The resolution cannot be about one man's -- or one family's -- insistence on clinging to power," Kerry said.
The response from the government delegation was firm and blunt.
"There will be no transfer of power, and President Bashar Assad is staying," Syrian Information Minister Omran al-Zoubi told reporters.
The two sides seemed impossibly far apart in opening statements in the Swiss city of Montreux, famed for its stunning mountain views and mellow jazz festival. The waterfront road was barricaded by roadblocks and hundreds of security forces, with boats patrolling the shores of Lake Geneva day and night.
The small-town venue was chosen in haste when a watchmakers' convention left Geneva hotels booked. That made for some potentially awkward encounters -- some of the opposition were staying in the same hotel as the Syrian government delegates, as were the Americans.
Complicating matters, Assad's delegates and the Western-backed opposition Syrian National Coalition both claimed to speak for the Syrian people. But the coalition has little sway with rebel brigades, who largely oppose talks with the government. And the government, Kerry said, has no legitimacy or loyalty among people devastated by war.
Overshadowing the conference was Ban's last-minute decision to invite -- and then disinvite -- Iran, which has funneled billions of dollars and Shiite fighters to Assad. Syria's civil war has become a proxy battle for regional dominance between Iran and Saudi Arabia, which funds many of the Islamist rebel movements and which Assad accuses of supporting al-Qaida-inspired militants streaming into Syria.
"Those who are behind the acts of terrorism in Syria should choose between being an arsonist or a fireman. They cannot be both at the same time," said Syrian U.N. Ambassador Bashar Jaafari. He said Syria's government had offered a cease-fire in Aleppo, although he did not spell out the terms, and rebel commanders say the government has used past truces to buy time.
Following Jaafari's hour-long speech, the opposition refused to make final remarks, minutes after sending out a tweet about their preparations.
Kerry suggested that as negotiations continued, the U.S. and its allies would step up their support for the opposition and look for different ways to wring concessions from Assad's government. But the Obama administration may be hampered by its unwillingness to act decisively in Syria so far.
Assad's forces have gained ground in recent months, and the Syrian leader's agreement to end his chemical weapons program turned out to be something of a diplomatic coup for him and his Russian supporters.
"The balance of power on the ground suggests he is going to stay," said Joshua Landis, the director of the Center for Middle East Studies at the University of Oklahoma. "Unless Kerry has got something up his sleeve, this might be a rhetorical flourish rather than a real commitment to the Syrian opposition."
Ban tried to put the best face on a difficult day and said the hardest work was yet to come.
"We did not expect instant breakthroughs. ... No one underestimated the difficulties," Ban said at the end of the day. "The Syrian people are looking desperately for relief from the nightmare in which they are trapped."