The UN envoy to Yemen has urged the country's government and Iran-backed Houthi rebels to revive efforts to agree a ceasefire deal and end the seven-year conflict there.
This plea follows failed efforts to extend a six-month truce that expired on Sunday.
“Any small incident could spark something that could have devastating consequences,” Hans Grundberg told Reuters in Amman on Tuesday.
“Luckily, we have not seen a military escalation, and this is so far so good.”
Mr Grundberg visited the rebel-held capital Sanaa for talks last week, and left without making any comment.
On Saturday, the Houthis said they considered the ceasefire to be at “a dead end”.
Mr Grundberg said on Sunday he would continue pushing for an extended and expanded deal between the government and the Houthis.
An initial two-month truce agreed in April was renewed twice, despite grievances by both sides over its implementation.
“So, I would urge all sides to exercise restraint and allow discussions that we have ongoing to bear fruit and … move Yemen out of the violence we have seen for the last seven years,” Mr Grundberg said.
He said the opposing sides failed to renew the truce because they were still far apart on the latest UN-brokered proposals to pay civil servants' wages, increase fuel shipments, add more air flights, open roads and speed military de-escalation.
A sticking point is a mechanism for paying civil servants that would benefit all Yemenis and alleviate their worsening economic plight, he said.
“It's complicated. It's one that has been on the table and the parties have wanted a resolution for a long period of time,” Mr Grundberg said.
An expanded deal was crucial to build on recent progress, the envoy said.
The government had accused the Houthis of being subservient to “foreign interests” when they refused to renew the truce on Sunday.
But a day later, Iran's foreign minister said there was a “need for the extension of the ceasefire in Yemen”, a statement published by state news outlet IRNA said.
Perks of the truce
Agreements have led to more fuel shipments from the main Red Sea port of Hodeidah and allowed commercial air flights to resume at Sanaa International Airport. Flights have carried more than 26,000 passengers to and from the capital.
“There has been progress here and we have the possibility of capitalising on this progress,” Mr Grundberg said.
The truce has led to a significant reduction of violence in a conflict that aid workers and officials say has killed tens of thousands, devastated the economy and left millions hungry.
Mr Grundberg said civilian and military casualties have gone down.
Houthi rebels ousted the internationally recognised government in 2014. A Saudi-led coalition intervened at the request of the government the following year.