The negotiations will be the first in two years between the Saudi-backed government and Houthi rebels supported by Iran since 2016, when 108 days of talks in Kuwait failed to broker a power-sharing deal.
The UN envoy for Yemen Martin Griffiths said on Wednesday that "consultations" in Geneva between the warring parties offered a "flickering signal of hope" after years of conflict.
The talks will be the first public meetings between the government of Abd Rabbu Mansour Hadi and Yemen's powerful Houthi rebels since 2016, when 108 days of negotiations in Kuwait failed to broker a power-sharing deal.
But both the government and the rebels have said they expect no breakthrough at the "consultations," which are due to open on Thursday but appear likely to be delayed.
TRT World 's Abubakr Al Shamahi brings more from Geneva, Switzerland.
'Signal of hope'
"The people of Yemen ... are desperately in need of a signal of hope. We would like to think that the work we will do together in these next days will begin to send a flickering signal of hope to them," Griffiths said.
While representatives of the Yemeni government arrived in Geneva on Wednesday, the rebels remained stranded in Sanaa, amid claims the Saudi-led coalition backing Hadi was preventing them from leaving for the talks.
When asked about the Houthi charges, Griffiths said, "We are working on that.
"I think it will sort itself out," he said. "If you look back at previous negotiations on Yemen, there has always been a delay.
"I don't take it very seriously. We will make it happen."
The UN meanwhile announced that there would be no meetings at its European headquarters in Geneva on Thursday as previously planned.
But Griffiths said his "informal consultations" with the government side would begin immediately.
"The government of Yemen ... is here already. I am looking forward to meeting their leader right after this, Foreign Minister Khaled al Yamani," he said at a press conference.
That meeting is expected to take place in a Geneva hotel, as are any other meetings that might happen on Thursday.
"So we are not going to waste time, and we are looking forward to getting our friends from Sanaa here and participating fully in the consultations."
Griffiths emphasised that the Geneva talks were "not formal negotiations," but said they aimed to pave the way towards bringing the parties back to the negotiating table.
The talks also seek to put in place a range of so-called confidence-building measures, which could mean prisoner swaps and the vaccination of children, he said.
"There is a chance for some tangible progress," he said, adding that he hoped to get the two sides to sit at the same table during the consultations, which are expected to last a couple of days.