President Trump signed an Executive Order temporarily suspending immigration into the U.S.
Proclamation Suspending Entry of Immigrants Who Present Risk to the U.S. Labor Market During the Economic Recovery Following the COVID-19 Outbreak | The White House
The 2019 Novel Coronavirus (COVID-19) has significantly disrupted the livelihoods of Americans. In Proclamation 9994 of March 13, 2020 (Declaring a Nation
President Trump has signed the Executive Order he alluded to in Monday evening’s Tweet. The Order lasts for 60 days, can be renewed, and affects people outside of the U.S. seeking immigrant status. It does not appear to pertain to nonimmigrant visas, such as the H-1B, TN, L-1, etc. You can find the entire Order here.