U.S. Secretary of State John Kerry called for a ceasefire in Syria in advance of a United Nations-directed 18-month transition in Syria. Kerry, meeting in Vienna Saturday with senior officials of 19 countries and groups, said efforts would be made to press the combatants to stop using weapons indiscriminately.

However, Kerry said the ceasefire would not apply to terrorist organizations such as the Islamic State group, formerly known as either ISIL or ISIS, and that no agreement had been reached on the future of Syrian President Bashar Assad.

We agreed on the need to begin formal negotiations between representatives of the Syrian opposition and the Syrian regime, under UN auspices, with a target date of the two sides actually sitting down negotiating with each other no later, hopefully, than a target date of around January 1st. That’s pushing. The group has agreed to work with Special Envoy de Mistura to assemble the broadest possible spectrum of the Syrian opposition – chosen by Syrians themselves – to define their negotiating positions and determine who their representatives to the talks will be.

We agreed on the steps – that the steps outlined in the 2012 Geneva communique present the best path forward towards an actual political transition, and we support a Syrian-led transition process within a target of six months that will: establish credible, inclusive and non-sectarian governance; set a schedule and a process for drafting a new constitution; and determine eligibility for voting and candidacy in elections.

We also agreed that free and fair elections would then be held, pursuant to the new constitution, within 18 months. These elections, we believe, would take place – not we believe – we agreed would take place under UN supervision with an emphasis on transparency and accountability, and with all Syrians, including the diaspora, eligible to participate."

Russian Foreign Minister Sergei Lavrov said no terrorism can be justified and that the world cannot stand idly by while it happens.

The meeting included top representatives of the U.N., European Union and Arab League. China and Iran sent deputy ministers. They agreed to speed up the transition process so elections could be held in 18 months.

"We face an environment now that bears little resemblance to the kind of black-white scenarios that make decisions relatively easy," Kerry said in a speech centered on Syria Thursday, the Associated Press reported. "Put simply, there are bad guys all around and good guys who are not accustomed to working with each other."

The meeting came in the wake of the series of terrorist attacks in Paris that left more than 120 dead and scores more injured Friday.

"We are in absolute and total agreement that these kinds of attacks are the most vile, horrendous, outrageous, unacceptable acts on the planet; that under any category -- we don’t know who did it, but they are acts of terror," Kerry said after a meeting with his Russian counterpart. "And the one thing we can say to those people is that what they do in this is stiffen our resolve -- all of us -- to fight back, to hold people accountable and to stand up for rule of law, which is exactly what we are here to do."

Lavrov agreed: "And just like there is no justification for terrorist acts, which is the position of the [U.N.] Security Council, I believe, as John said, there will be no justification for us not doing much more to defeat ISIL, al-Nusrah and the like [in Syria]. And I hope that this meeting as well would allow us to move forward."