Antalya, Turkey( CNN) President obama said Sunday “the skies have been darkened” in the aftermath of a terrorist killing spree in Paris on Friday.

Speaking at the start of the G20 here on the Turkish Riviera, Obama said the two-day summit has assumed new important as leaders work to develop a response to the massacre.

“The killing of innocent people based on a distorted ideology is an attack not just on France , not only on Turkey, it is an attack on the civilized world, ” Obama said during a meeting with Turkish President Recep Tayyip Erdoan.

“We stand in solidity with( the French people) in hunting down the perpetrators of this crime and bringing them to justice, ” Obama said, adding afterward that he and Erdoan discussed ways to fortify Tukey's border with Syria and a strategy for addressing the refugee crisis

“We will redouble our efforts, working with other members of the coalition, to bring about a peaceful transition in Syria and to remove( ISIS) as a force that can create so much pain and suffering for people in Paris, ” Obama said.