Syria's government delegation will arrive a day late in Geneva to take part in a new round of talks with the opposition, officials have said.
The delay appears to reflect the government's displeasure with the opposition's insistence that President Bashar Assad must leave at the start of any transitional period.
The United Nations is scheduled to resume the talks between the government and the Syrian opposition in the Swiss city today.
The opposition delegation arrived yesterday after publishing a communique last week that said it was ready for talks "without preconditions", meaning its participation was not dependent on the departure of Assad.
However, it said it still held its belief that Assad would need to step down at the start of any transitional period for any settlement to the nearly seven-year civil war to succeed.
"I can confirm we have received a message from government of Syria indicating that their delegation would arrive tomorrow," said Michael Contet, an adviser to UN special envoy to Syria Staffan de Mistura.
A Syrian foreign ministry official in Damascus also said the delegation would take part in talks starting tomorrow afternoon, headed by Bashar Ja'afari, Syria's representative at the UN.
As in previous talks, a major point of disagreement between the two sides will be the future of Assad.
Damascus has refused to negotiate over his future in any talks with the opposition. It says it wants to focus on defeating "terrorism", its word for armed opponents of the Syrian president.
The head of the opposition delegation, Nasr Hariri, told reporters yesterday that the opposition was "ready to negotiate", and accused the government of stalling: "The thing the regime is most afraid of is political negotiations.
"We assert that a political transition that achieves Assad's departure at the beginning of the transitional period is our goal."
The delegation was expanded last week under Saudi Arabian auspices to include opposition groupings seen by Damascus as more palatable for negotiations, including the so-called "Moscow group", which has resisted calling for Assad's departure.
Mr Hariri said the reformulation removed any excuse by the government and its chief diplomatic backer, Russia, to circumvent the UN talks.
Mr de Mistura stressed he would "not accept any preconditions by any party", and said the talks would be guided by a 2015 Security Council resolution mandating a political transition for Syria.
This latest round of Geneva talks, the eighth since 2012, will focus on getting to an "inclusive process" to draft and ratify a new constitution, said Mr de Mistura.
He hailed a "useful" meeting with diplomats from the five permanent Security Council members, while calling on the rival sides in the war-torn country to get down to "business".