From the Document: "On June 22, President Trump issued a proclamation that, among other provisions, extends Proclamation 10014 issued April 22 suspending the entry into the United States of certain aliens (foreign nationals) who are seeking lawful permanent resident (LPR) status (i.e., immigrants). Both proclamations justify the suspension as protecting American workers from foreign labor market competition during a time of high domestic unemployment and reduced demand for workers caused by the coronavirus pandemic. Both proclamations rely on two immigration-related legal authorities. Under the Immigration and Nationality Act (INA), §212(f) (8 U.S.C. §1182(f)), the President may suspend immigration when it would harm U.S. interests. Under INA §215(a) (8 U.S.C. §1185(a)) the President may prescribe limitations and exceptions on who may enter or depart the country."
CRS Insight, IN11362
Congressional Research Service: https://crsreports.congress.gov/