ANTALYA - World leaders on Monday committed to join forces to bring peace to Syria and destroy the Islamic State jihadist network, hoping to curb the extremist menace after the Paris attacks.

Leaders of the Group of 20 top economies meeting in Turkey described the Paris gun and bombing assaults as an “unacceptable affront to all humanity”, according to a rare separate statement accompanying the final communique after their annual summit.

Concretely, they will share intelligence to crack down on the movement of foreign fighters across borders, the statement said. They also urged “all states” to come to share the burden of refugees, with hundreds of thousands pouring out of war-torn Syria to take the often dangerous path to Europe.

Western leaders sought in particular to narrow important differences with Russian President Vladimir Putin on resolving the conflict in Syria and fighting the Islamic State group. G20 leaders showed “our resolute stance in the fight against terrorism,” said host Turkish President Recip Tayyip Erdogan at a news conference wrapping up the summit.

The urgent need to coordinate action on Syria after the Paris attacks that killed 129 people dominated the summit’s agenda, but leaders also pressed ahead with a drive to stave off catastrophic climate change.

British Prime Minister David Cameron said the split between the West and Russia on Syria narrowed during talks in Vienna this weekend but more work needed to be done to unify positions. “There is still a very big gap but I think there is still some hope that this process could move faster in the future than it has in the past,” he said after a bilateral meeting with Putin.

But he lamented how the “body count had piled up in Syria” over the course of several international summit meetings since the start of the war. “The faster we can degrade and destroy (IS) the safer we will be,” he said.

Russia has refused to abandon its support for Syrian President Bashar al-Assad in the four-year civil war, which has claimed more than a quarter of a million lives and displaced millions. Moscow recently stepped up its involvement in Syria with a bombing campaign of its own that has been welcomed by the regime but greeted with suspicion in the West.

US President Barack Obama on Sunday held one of his most intimate discussions yet with Putin, both men seen hunched over a coffee table in animated, impromptu talks on the sidelines of the summit. US officials said the two leaders agreed on the need for a political transition for Syria that would be set up by a ceasefire and UN-brokered talks. The Kremlin said the two sides shared the same goal of fighting Islamic State but differed on tactics.

The stepped-up diplomacy came after world powers agreed in the Vienna talks at the weekend on an outline for political transition for Syria, but crucially not on what should happen to Assad. Erdogan on Monday reiterated his tough stance against Assad “who massacred his own people”, saying the Syrian leader had “no place” in the country’s future.

In the special statement at the end of the G20 gathering, world leaders raised the alarm over an “acute and growing flow of foreign terrorist fighters”. They vowed to share intelligence, track border crossings and boost aviation security to halt the movement of jihadist fighters. German Chancellor Angela Merkel called for “intensive cooperation” between intelligence agencies as well as the military in the fight against terror.

Britain is to host a major donor conference in London in February 2016 to rally aid for Syrian refugees, she added in comments confirmed by Cameron. Despite the heavy shadow cast by the attacks in Paris, world leaders pressed on with their original agenda, pledging in a draft to agree legally-binding goals on climate change at a conference in Paris later this month but making no mention of whether they will help developing countries meet the targets. The G20 summit next year moves to China, followed by Germany in 2017.