World leaders have vowed to do more to share intelligence, cut off funding to terrorists, and strengthen border security in Europe in the wake of the deadly terror attacks in Paris.
German Chancellor Angela Merkel made the announcement as leaders from the G20 rich and developing nations wrapped up a two-day summit in Turkey on November 16.
Merkel said G20 leaders agreed the terror challenge could not be tackled by military means alone.
U.S. President Barack Obama conceded that the Paris terror attacks were a "terrible and sickening setback" in the fight against the Islamic State, but indicated no shift in his approach to defeating the extremist group.
"The strategy that we are putting forward is the strategy that is ultimately is going to work," Obama said. "It's going to take time."
Obama said sending U.S. ground troops into Syria "would be a mistake" unless the United States was committed to being a permanent occupying force in the region.
Obama said the United States would intensify its campaign of air strikes and arming and training moderate forces. And he called on other nations to step up their involvement in the fight against the extremists.
Russian President Vladimir Putin emphasized the need to cut off the Islamic State's 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.
Cameron, who met separately with Putin on November 16, said a "very big gap" remained between Western powers and Russia over the best way of ending the Syria war, but there were signs of a willingness to compromise on all sides.