Envoys from major states and regional powers who are attending the Syria talks on Saturday in Vienna condemned the deadly attacks in Pairs last night.
"These kinds of attacks are the most vile, horrendous, outrageous, unacceptable acts on the planet," US Secretary of State John Kerry said.
"And the one thing we could 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," he added.
Russian Foreign Minister Sergei Lavrov said "no justification for terrorist acts, and no justification for us not doing much more to defeat
ISIS."
Before the meetings, French Foreign Minister Laurent Fabius told reporters the attacks in Paris made it more necessary for the world community to find a common approach to Syria and terrorism.
EU foreign policy chief Federica Mogherini said no one could turn away from the common threat, referring to the attacks which have left more than 120 people dead and about 200 wounded.
Nasser Judeh, Jordan's foreign minister, said the attacks reaffirmed the collective commitment to fight terror and extremism.
The world major states and regional powers on Saturday gathered in Vienna to find a solution to end the ongoing crisis in Syria, but the meeting is overshadowed by the deadly attacks in Paris.
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