48 USC 1908 - Transitional immigration rules

(a) Citizen of Northern Mariana Islands 
Any person who is a citizen of the Northern Mariana Islands, as that term is defined in section 24(b) of the Act of December 8, 1983 (97 Stat. 1465), is considered a citizen of the United States for purposes of entry into, permanent residence, and employment in the United States and its territories and possessions.
(b) Termination 
The provisions of this section shall cease to be effective when section 301 of the Covenant to Establish a Commonwealth of the Northern Mariana Islands in Political Union With the United States (Public Law 94241) becomes effective pursuant to section 1003(c) of the Covenant.