BISMARCK, N.D. — The Army Corps of Engineers said it has ‘‘no plans for forcible removal’’ of campers in North Dakota who have been protesting against the Dakota Access oil pipeline.

The corps said it ‘‘is seeking a peaceful and orderly transition to a safer location.’’

The Corps of Engineers notified tribal leaders Friday that all federal lands north of the Cannonball River will be closed to public access Dec. 5 for ‘‘safety concerns’’ related to the demonstrations and because of winter weather.

The agency said those who choose to stay do so at their own risk.

Corps officials said anyone on the property north of the Cannonball River after that date will be trespassing and subject to prosecution. The land to be closed includes the main protest camp, about 50 miles south of Bismarck.

The county sheriff leading the response to the protests has defended his office’s handling of the demonstrations, which he believes have become increasingly aggressive.

‘‘We are just not going to allow people to become unlawful,’’ said Morton County Sheriff Kyle Kirchmeier, a veteran of the North Dakota Highway Patrol and National Guard who was elected to his first term as sheriff about two years ago. ‘‘It’s just not going to happen.’’

More than 525 people from across the country have been arrested during months of protests over the four-state, $3.8 billion pipeline, all here in support of the Standing Rock Sioux tribe that’s fighting the project because it believes it threatens drinking water and cultural sites on their nearby reservation.

Associated Press