President Donald Trump’s June 22, 2020 presidential proclamation limits the entry of certain nonimmigrants into the United States starting on June 24, 2020 through December 31, 2020. The proclamation impacts individuals that were outside of the US on June 24, 2020 and did not already hold a valid US visa or travel document. Impacted visa categories include H, L, or J visa workers and their dependents.
Canadians are exempt from the proclamation, because they do not need an H, L, or J visa to enter the United States. Local Customs and Border Patrol (CBP) agents are aware of the issue.
 American Immigration Lawyers Association (AILA) Doc. No. 20062436