ANTALYA, Turkey -- World leaders vowed Monday to boost intelligence-sharing, cut off terrorist funding and strengthen border security in Europe, as they sought to show resolve and unity following the Islamic State's deadly terror attacks in Paris.
U.S. President Barack Obama said the militant group was "the face of evil" and urged other nations to do more to combat the threat it poses. Still, he resisted calls to escalate U.S. military action and open a large-scale ground war, saying he would instead intensify the American-led airstrike campaign, as well as efforts to train and equip moderate rebels.
"We need to be doing everything we can to protect against attacks and protect our citizens," Obama said at a news conference closing two days of talks with leaders from the Group of 20 rich and developing nations.
Added German Chancellor Angela Merkel: "We agreed that the challenge can't just be tackled with military means, but only a multitude of measures."
While the summit resulted in plenty of tough talk and blistering condemnations of the Paris attacks, leaders spoke mostly in broad strokes of their pledges to intensify the anti-Islamic State campaign.
Russian President Vladimir Putin emphasized the need to cut off the militants' ability to generate revenue through oil smuggling. And British Prime Minister David Cameron announced plans to host a donor conference early next year to raise "significant new funding" to tackle the flood of refugees spilling out of Syria.
"None of this is a substitute for the next urgent need of all: to find a political solution that brings peace to Syria and enables the millions of refugees to return home," Cameron said.
The leaders' meeting came against the backdrop of heavy French bombardment of the Islamic State's stronghold in Syria. The U.S. was expanding its intelligence sharing with the French and helping them identify targets, according to American officials.
The G-20 meeting in the Turkish seaside resort of Antalya was planned long before the Paris attacks, which left at least 129 people dead and hundreds wounded. But the violence intensified the discussions, resulting in a flurry of meetings on the sidelines of the summit about the situation in Syria, where the 4 1/2-year civil war has created a vacuum for the Islamic State to thrive.
Leaders are particularly concerned that the militants appear to be increasingly focused on striking targets outside their base in Iraq and Syria. In addition to Paris, the group has claimed responsibility for attacks in Lebanon and Turkey, as well as the downing of a Russian airplane in Egypt.
Obama huddled Monday with European leaders from France, Britain, Germany and Italy. French President Francois Hollande skipped the summit to stay home and deal with the aftermath of the attacks, but Foreign Minister Laurent Fabius participated in the discussion.
Putin, a key player in ending the conflict in Syria, met separately with Italian Prime Minister Matteo Renzi and Cameron. Russia is Syrian President Bashar Assad's biggest benefactor and has helped keep him in power.
Putin launched an air campaign in Syria a month-and-half ago with the Islamic State as the top declared target. The U.S. and its allies, however, have accused Moscow of focusing on other rebel groups in a bid to again shore up Assad, whom the West sees as the main cause of the Syrian conflict and the chief obstacle to peace.
In his own news conference at the end of the summit, Putin dismissed those criticisms and called on global powers to join forces to destroy the Islamic State.
"Life is changing fast, and it often teaches us lessons," Putin said. "The understanding gradually comes that we can only fight efficiently if we do it together."
Nearly five years of clashes between Assad's forces and opposition groups have left more than 250,000 people dead and spurred a massive refugee crisis in Europe.
Ahead of the G-20, foreign ministers met in Vienna to discuss a new diplomatic plan to end the Syrian war. The plan appears to be based largely on a Russian proposal that envisions negotiations between Assad's government and opposition groups starting by Jan. 1.
Still, sharp differences over Assad's future and disagreements about what militant groups in Syria should be considered terrorists have dampened hopes for a breakthrough.
The Vienna talks were high on the agenda when Obama and Putin huddled for about 35 minutes Sunday on the sidelines of the G-20. The two leaders spoke again briefly Monday, a conversation Putin said focused on a new Russian proposal to restructure Ukraine's debt as a December deadline to pay $3 billion back to Moscow nears.
Obama said had "some degree of hope" that the latest round of discussions on Syria's future might succeed.
