The global body’s Syria envoy Staffan de Mistura said there was a clear agenda for another round of talks.
“I am planning to invite Syrian invitees back here in March for a fifth round,” De Mistura said.
Russia and Syrian regime officials have floated March 20 as a possible date.
De Mistura said the warring sides, which are communicating through proxy, agreed to discuss four settlement issues in parallel; namely governance, constitution, elections and counterterrorism.
He announced a trip to New York in the next few days to brief UN Secretary-General Antonio Guterres and the Security Council.
The next Astana talks, with Turkey and Iran participating, are also expected to take place within the next fortnight.
The exchange of detainees, abductees and missing people will also be raised in the upcoming Astana meeting, de Mistura said.
Head of the Syrian opposition, Nasr al-Hariri said they provisionally accepted the 12 principles offered to both delegations
"We are closing this round without clear results," Hariri told reporters after meeting de Mistura, while adding that this round was more positive with regard to the discussion on political transition.
"De Mistura gave us a 'nonpaper' that includes 12 items. These are general provisions... These provisions are initially accepted. We have some additional remarks. We will give them to de Mistura... These remarks are just to enrich this paper," Hariri said.
Hariri received a question criticizing Turkey's Operation Euphrates Shield against terror groups in Syria.
"I wanted to hear from you about the Russian occupation and Iranian occupation that are taking place,” he said in response.
“War planes of at least 64 countries that are flying all over skies over Syria. In addition to Israeli airplanes that are bombarding areas around Damascus, which may be near your house. So, where is the national sovereignty after all of this?
"Turkey is a friendly country; there are 3,2 million Syrians living in Turkey; maybe you have some relatives living there," he added.
The latest round of peace talks over the six-year conflict began on Feb. 23. It follows a similar but abortive effort last year in April.
Both sides were in the same room on the first day last week to hear de Mistura call for an end to the war. “The Syrian people desperately want an end to this conflict and you all know it,” he said. “You are the first ones to tell us it.”
However, the opposing delegations have yet to talk vis-a-vis.
Since civil war in Syria erupted in March 2011, more than 250,000 people have been killed, according to the UN. The Syrian Center for Policy Research puts the death toll at more than 470,000.
The war has also left nearly half of the population displaced.