Foreign Secretary William Hague said it was "clear" the Assad regime was responsible for the breakdown of the Geneva peace talks.
Syrian regime clearly responsible for breakdown of the Geneva talks. UNSC must now act to address the humanitarian crisis urgently
International mediator Lakhdar Brahimi apologised to the Syrian people on Saturday for the lack of progress at peace talks in Geneva after their second round ended with little more than an agreement to meet again.
The Algerian-born diplomat said the agreement to evacuate people from the besieged city of Homs had raised hopes that had not been satisfied at the Geneva talks, involving opposition groups and representatives of President Bashar al-Assad.
Syria's opposition has said they are "disappointed" for the lack of progress in peace talks at Geneva, after a third round of talks ended with no resolution.
Opposition spokesman Louay Safi told journalists after the talks: "I am very sorry to say really there is nothing positive we can take."
Syrian government and opposition delegations ended a third round of Syria peace talks in Geneva with no agreement on a date for a third round nor a mechanism for the agenda.
For Syria's envoy to the United Nations, Bashar Al-Jaafari, who is part of the Syrian government delegation, it was the opposition's own interpretation for the agenda that caused the disagreement on both sides.
"We accepted the draft agenda proposed by the international mediator, the disagreement started when the other side started presenting their own interpretation for the agenda...
"So in other words, they wanted the discussion about fighting terrorism to stay open with no end, and all they care about it is to move to the second clause, move to the second clause without a common reading for the terrorism subject," Al-Jaafari told journalists.
Al-Jaafari assured the Syrian people they will return for a third round of talks.
UN-Arab League mediator Lakhdar Brahimi ended direct talks between the Syrian government and opposition without finding a way of breaking the impasse in peace talks.
Saturday's talks, which lasted less than half an hour, left the future of the negotiating process in doubt and no date was set for a third session.
Brahimi told a news conference that both sides agreed that the agenda for the next round should focus on four points: ending the violence and terrorism, creating a transitional governing body, building national institutions, and reconciliation.
He also apologised to the Syrian people, saying they had "high hopes", but that ultimately the second round of talks "have not helped them very much".