UN Syria envoy Staffan de Mistura has urged Russia, Iran, and Turkey to conduct further Syrian cease-fire talks as soon as possible to prevent conditions in the war-ravaged country from worsening.
De Mistura was speaking on March 24 in Geneva, where he is mediating separate talks in search of a political solution to the six-year Syrian civil war.
Russia, Iran, and Turkey brokered a cease-fire in Syria that took effect on December 30.
The three countries are sponsoring talks in the Kazakh capital, Astana, to develop systems to monitor and improve the cease-fire.
De Mistura urged the co-sponsors to recapture the momentum and "hopefully there will be an Astana meeting as soon as possible in order to control the situation which at the moment is worrisome."
De Mistura said he was not expecting "miracles" but was hoping for "incremental steps."
Russia, Iran, and Turkey attended the most recent Astana talks on March 14, but Syrian opposition groups did not attend, accusing the Syrian government and backer Russia of failing to honor the cease-fire.
Two previous rounds of Astana talks ended without a breakthrough.
The war in Syria, which began with a government crackdown on pro-democracy protesters in March 2011, has killed an estimated 300,000 people and displaced millions more.
Russia and Iran back President Bashar al-Assad, while Turkey and the United States support various rebel groups fighting the government.