The President shall find that any required environmental impact statement relative to the Alaska natural gas transportation system designated for approval by the President has been prepared and that such statement is in compliance with the National Environmental Policy Act of 1969 [
42 U.S.C.
4321 et seq.]. Such finding shall be set forth in the report of the President submitted under section
719e of this title. The President may supplement or modify the environmental impact statements prepared by the Commission or other Federal officers or agencies. Any such environmental impact statement shall be submitted contemporaneously with the transmittal to the Senate and House of Representatives of the President’s decision pursuant to section
719e
(b) of this title or subsection (b) of this section.