By JOHN-THOR DAHLBURG Associated Press

NATO defense ministers have agreed to more than double the size of the alliance's Response Force to meet simultaneous challenges from Russia and armed Islamic extremists.

The foreign ministers on Thursday also decided to form a new quick-reaction force of 5,000 ground troops that could begin deploying within 48 hours.

NATO Secretary-General Jens Stoltenberg said the decisions made during a daylong meeting at alliance headquarters will "ensure that we have the right forces in the right place at the right time."

U.S. Defense Secretary Chuck Hagel and counterparts from NATO's other 27 member nations also ordered the creation of command-and-control centers in the capitals of the three Baltic states as well as in Poland, Romania and Bulgaria.