A district court of the United States shall have jurisdiction specifically to enforce, and to prevent and restrain a person from violating an order, rule, or regulation issued under this chapter.

A civil action authorized to be brought under this subsection 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 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 a person who committed such violation or by administrative action under subsection (b).