Obama vows to help France hunt down perpetrators of Paris terror attacks

President Obama opened two days of talks with world leaders here Sunday by vowing to help France in “hunting down the perpetrators” of the terrorist attacks in Paris, but White House officials said the administration had no plans to alter its strategy to defeat the Islamic State.

Shortly after arriving at the Group of 20 summit, Obama met with Turkish President Recep Tayyip Erdogan and later huddled informally with Russian President Vladi­mir Putin amid questions about how the international community will respond to the mass killings claimed by the radical...