The several district courts of the United States are vested with jurisdiction specifically to enforce, and to prevent and restrain any person from violating, any order or regulation made or issued under this chapter.

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 chapter, or any order or regulation issued under this chapter, if the Secretary believes that the administration and enforcement of this chapter would be adequately served by providing a suitable written notice or warning to the person who committed such violation or by administrative action under subsection (c).