Immigration and Nationality Act (INA)

8 U.S.C. Section 1182 (f):

Whenever the President finds that the entry of any aliens or of any class of aliens into the United States would be detrimental to the interests of the United States, he may by proclamation, and for such period as he shall deem necessary, suspend the entry of all aliens or any class of aliens as immigrants or nonimmigrants, or impose on the entry of aliens any restrictions he may deem to be appropriate.

8 U.S.C. Section 1152 (a) (1) (A):

[N]o person shall be discriminated against in the issuance of an immigrant visa because of the person's race, sex, nationality, place of birth, or place of residence.