A district court of the United States shall have jurisdiction specifically to enforce, and to prevent and restrain any person from violating, any order or regulation made or issued by the Secretary under this subchapter.

A civil action authorized to be brought under this section shall be referred to the Attorney General for appropriate action, except that the Secretary is not required to refer to the Attorney General a violation of this subchapter, or any order or regulation issued under this subchapter, if the Secretary believes that the administration and enforcement of this subchapter would be adequately served by administrative action under subsection (c) or suitable written notice or warning to the person committing the violation.