A record of lawful admission for permanent residence may, in the discretion of the Attorney General and under such regulations as he may prescribe, be made in the case of any alien, as of the date of the approval of his application or, if entry occurred prior to July 1, 1924, as of the date of such entry, if no such record is otherwise available and such alien shall satisfy the Attorney General that he is not inadmissible under section 1182(a)(3)(E) of this title or under section 1182(a) of this
(a)General. Except as provided in paragraph (b)(1) of this section, each arriving alien applying for admission (or boarding the vessel or aircraft on which he or she arrives) into the United States for lawful permanent residence, or as a lawful permanent resident returning to an unrelinquished lawful permanent residence in the United States, shall present one of the following: (1) A valid, unexpired immigrant visa; (2) A valid, unexpired Form I-551, Permanent Resident Card, if seeking readmission