TALLINN, Estonia (AP) — President Barack Obama said Wednesday that the United States will not be intimidated by Islamic State militants after the beheading of a second American journalist and will build a coalition to “degrade and destroy” the group.

Obama still did not give a timeline for deciding on a strategy to go after the extremist group’s operations in Syria. “It’s going to take time for us to be able to roll them back,” the president said at a news conference during a visit to Europe.