International talks aimed at bolstering the peace process for Syria have come to an end in Vienna without a new date being scheduled to restart peace talks.
But parties at the May 17 meeting of senior diplomats from Russia, the United States, Europe, and the Middle East vowed to do what they can to strengthen a shaky cease-fire between Syrian President Bashar al-Assad's forces and moderate opposition fighters.
U.S. Secretary of State John Kerry said at the end of the talks that there was an agreement on "consequences for any side's actions that have an agenda other than trying to reach an agreement and trying to reach peace."
The UN's Syria envoy Steffan de Mistura said that the next round of peace talks "can’t wait too long."
Kerry and Russian Foreign Minister Sergei Lavrov co-chaired the Vienna meeting.
They have been struggling to secure a fragile February cease-fire, which has disintegrated into waves of fierce fighting.
Even shakier are hopes of forging a so-called "political settlement" that would set up a transitional government in Syria and move the country toward elections.
U.S. officials say Kerry still insists that Assad should step down from power as part of that political settlement.
Kerry has also set an August 1 deadline for agreeing to a political transition period for Syria.
But Assad, bolstered by military support from Russia and Iran, shows no sign of stepping down from power.
An aide to Kerry said after talks between Lavrov and Kerry on May 16 that the United States was "talking to the Russians, trying to get a better environment for the political negotiations."
But Kerry's aide said Assad's regime "is just not there, and I think that's really the key to it."
Lavrov told reporters after the May 17 talks that Russia does not support Assad's regime but is backing the Syrian Army's fight against terrorist groups.