The rival delegations enter and leave the room through separate doors. They don’t shake hands. They avoid eye contact and address one another only through their U.N. mediator to avoid replicating the bitterness of the battlefield in this first-ever effort to negotiate an end to Syria’s war.

That the delegations have communicated at all in the past five days can be counted as an achievement, diplomats say, given the hatreds engendered by a conflict that escalated from protests to shelling, ballistic missiles, beheadings and chemical weapons.

So far, however, the brief encounters here have yielded little beyond reminders of the breadth of the divide between those seeking to end the rule of Syrian President Bashar al-Assad and those whose declared goal is to preserve his power.

It is as if the negotiations have merely relocated the bloody stalemate to the refined environment of Geneva, where the talks are taking place at the European headquarters of the United Nations.

Members of the government delegation, staying at the fashionable Hotel de la Paix overlooking Lake Geneva, say they have had no encounters outside the formal meetings with their opposition counterparts, who are staying a half-mile away at the less opulent Royal Hotel near the railway station.

“There’s been nothing of confidence-building or trust,” said a Syrian journalist who is close to the government and spoke on the condition of anonymity because of sensitivities surrounding the talks. “There’s no handshaking, speaking, nothing. It’s very tense, very cool.”

The hope is that by exposing the foes to one another and letting them air their fears and aspirations, some form of common ground will emerge.

On Wednesday, U.N. special envoy Lakhdar Brahimi reported some progress on that front.

“The ice is breaking slowly, but it is breaking,” he said.

But if there is common ground, it hasn’t appeared yet, he acknowledged.

“To be blunt, I don’t expect we will achieve anything substantial,” he said of this first round of talks, which are expected to adjourn Friday and resume after about a week.

In the absence of progress in the meeting room, the war has relocated to the corridors of the stately U.N. headquarters and the lawn outside, where representatives of the rival delegations compete to deliver their version of events.

Opposition journalists, many of them activists in the protest movement, hound government delegates with questions they are unaccustomed to facing in the Syrian capital, Damascus, where the government retains a tight hold even as other parts of the country have slid beyond its control.

“Don’t you think it is a shame for the Assad regime to use food as a political bargaining point?” opposition journalist Ahmed Zakaria asked the deputy foreign minister, Faisal Mekdad, at a news conference this week. He was referring to the effort to negotiate access for an aid convoy to the besieged center of the city of Homs.

“Those are allegations promoted by the terrorist groups. Perhaps you are one of them,” Mekdad shot back.

For most on both sides, this is the first encounter they have had with the opposing camp since demonstrations against Assad’s rule erupted in 2011. The launch of the peace effort, in the Swiss town of Montreux last week, brought some predictably hostile exchanges in the conference hall where rival media factions gathered.

“Shame on you,” a correspondent for an opposition television station screamed at a journalist for the state-controlled media, who wore a button bearing Assad’s portrait pinned to his lapel. “You are wearing the picture of a murderer.”

“And you are a terrorist,” the journalist yelled back, an exchange that summed up the essence of the divide.

There have been some cautious outreaches, too, glimmers of the kind of convergence that Brahimi hopes will eventually bring the sides together. Activist Rami Jarrah, who is covering the event for an opposition news outlet, described a discreet conversation on the sidelines of a news conference with a representative of a pro-
regime news organization who appeared to offer sympathy for Assad’s opponents.

The government reporter first asked whether Jarrah and his colleague, Adnan Hadad, an activist from Aleppo, were recording the conversation. He insisted on checking their phones to ensure that they weren’t.

“He said, ‘I know not all of you are Salafists,’ ” Jarrah recalled. “He said, ‘If you had stayed peaceful, I would have joined you,’ ” — a reference to the protest movement’s evolution to armed revolt in 2011.

But Jarrah failed to convince the man that it was the government’s use of firepower to suppress the demonstrations that prompted regime opponents to resort to arms. Since then, when they encounter each other in the U.N. hallways, each looks the other way.

“There’s no point in talking to them anymore,” Hadad, an activist with the Aleppo Media Center, said of government journalists. “They are like government robots. They are programmed to promote government strategy.”

Fear deters many in the official delegation and the news corps accompanying them from speaking openly, said Ahmed Fakoury, a former state television anchor and adviser to Bouthaina Shaaban, one of Assad’s closest advisers and a top member of the government delegation.

Fakoury, who defected in 2012 and now advises the opposition, sought out old friends among the government delegation when talks began last week. He was shunned.

“I said hello to one of them,” Fakoury recalled. “He said, ‘I don’t know you. I’ve never seen you before.’ ”