At times the warlike rhetoric emanating from the alabaster walls of the UN offices along the banks of Lake Geneva has reinforced animosities, disorienting even seasoned diplomats.

"Is it evening or afternoon?" UN mediator Lakhdar Brahimi said yesterday after hours of shuttling between the two sides. Even Mr Brahimi conceded the talks were likely to go nowhere this week. "To be blunt, I don't think we will achieve anything substantive," he said.

Officials said yesterday the talks would pause today and resume a week later, to give the sides time to reflect.

Meanwhile, the war raged on in Syria, with activists saying the government bombardment of Aleppo and Homs has intensified since the talks began.

The impasse stems from a disagreement over the talks' goal. Both sides signed on to this week's meetings by endorsing the 2012 Geneva I communique, which calls for the establishment of a transitional government by "mutual consent". The opposition is determined to use Geneva I as grounds to remove President Bashar al-Assad from office. That approach has been steadfastly dismissed by regime delegates, who have instead tried to focus on fighting terrorists - what they call the rebel forces.

The Assad delegates also are trumpeting plans to further enshrine his leadership by holding presidential elections in June.

With no progress in sight, both sides have resorted to using the conference as a public platform to criticise and isolate their adversaries on the diplomatic stage.

"They've been bluffing all along," said Syrian opposition coalition president Ahmad Jarba, referring to the regime. "Geneva ... was the moment of truth."

After days of posturing, Mr Brahimi this week finally turned the discussions to the main goal of the conference - political transition. But the government countered by submitting a "political communique" demanding the opposition and its Western backers commit to "restore all (Syria's) occupied territories" - a reference to the Israeli-controlled Golan Heights. The document defended Syria as a legitimate democracy, saying: "Syrians decide the future of their country through democratic means and the ballot box."

The regime's defence of Syria's political system has grated on the opposition and its Western backers. Assad's father, an air force pilot, seized power in a 1971 coup and after his death in 2000 power passed to his son Bashar. Both have suppressed any opposition to their rule.

Although the government amended the constitution in 2012 to allow for multi-party elections, the opposition boycotted that year's parliamentary polls, dismissing them as neither free nor fair. The Syrian parliament remained filled with Assad loyalists.

But Ayham Kamel, an analyst with the Eurasia Group think tank, said the opposition should not reject elections outright, provided the polls are monitored by international observers.

. The conference has also become a setting for each side to jockey for tactical advantages back on the battlefield. More than a week before the conference, the regime received a UN proposal to allow humanitarian convoys to enter the besieged parts of Homs, according to Western diplomats. The plan, diplomats said, was supposed to win quick approval and build momentum for the talks.

When the regime and opposition finally faced off last weekend from opposite ends of a U-shaped table, the Assad government's stone-faced delegate Bashar Ja'afari informed the room he was unaware of the plans to help Homs, according to diplomats.

Syrian officials swiftly characterised the humanitarian convoys as a trick aimed at helping besieged rebel forces rather than civilians. A counterproposal by the regime - to allow women and children to leave Homs's historical quarter - was rejected by opposition delegates who labelled it an attempt to lure rebels into deserting their positions. "The regime is trying to steer us away from the process," Louay Safi, a delegate for the opposition, said this week.

THE WALL STREET JOURNAL