United Nations:
White House officials say the United Nations Security Council is expected to pass a resolution requiring nations to prosecute their citizens who travel abroad to join terrorist organizations.
The binding resolution would be part of a U.S.-led effort to galvanize the international community against what Obama administration officials call an "unprecedented" threat from extremists flocking to Syria and Iraq.
White House officials touted the measure on Monday as a significant step in their effort against the Islamic State group and other militant organizations that are drawing Europeans, Americans into their violent orbit.
But they acknowledged that the UN resolution has no enforcement mechanism and that the international community has no single definition of what constitutes a terrorist group.