As soon as practicable after July 1, 1977, but not later than September 1, 1977, the President shall issue a decision as to whether a transportation system for delivery of Alaska natural gas should be approved under this chapter. If he determines such a system should be so approved, his decision shall designate such a system for approval pursuant to section 719f of this title and shall be consistent with section 719c(b)(1)(C) of this title to assure delivery of Alaska natural gas to points both east and west of the Rocky Mountains in the continental United States. The President in making his decision shall take into consideration the Commission’s recommendation pursuant to section 719c of this title, the report under section 719c(c) of this title, and any comments submitted under section 719d of this title; and his decision to designate a system for approval shall be based on his determination as to which system, if any, best serves the national interest.

The President, for a period of up to 90 additional calendar days after September 1, 1977, may delay the issuance of his decision and transmittal thereof to the House of Representatives and the Senate, if he determines (A) that there exists no environmental impact statement prepared relative to a system he wishes to consider or that any prepared environmental impact statement relative to a system he wishes to consider is legally or factually insufficient, or (B) that the additional time is otherwise necessary to enable him to make a sound decision on an Alaska natural gas transportation system. The President shall promptly, but in no case any later than September 1, 1977, notify the House of Representatives and the Senate if he so delays his decision and submit a full explanation of the basis of any such delay.