Los Angeles ? The Navy can use high-intensity sonar for Pacific warfare exercises but must stay away from some sensitive marine habitat and increase monitoring for whales, under an agreement reached Friday with environmental groups.

Four days earlier, a judge banned the sonar because of concerns it could harm marine mammals.

The settlement prevents the Navy from using the sonar within 25 miles of the newly established Northwestern Hawaiian Islands Marine National Monument during its Rim of the Pacific 2006 exercises, and imposes a variety of methods to watch for and report the presence of marine mammals.

The Navy said it could begin using the sonar as soon as this weekend.