U.S. extends border closures with Canada, Mexico until Aug. 21

July 21 (UPI) -- The U.S. government has decided to keep borders with Canada and Mexico closed through at least Aug. 21, official records showed Wednesday.

The document said the sustained human-to-human coronavirus transmissions and risks posed by new variants "increased risk of exposure to the virus associated with COVID-19."

"Given the outbreak and continued transmission and spread of COVID-19 within the United States and globally, [Homeland Security Secretary Alejandro Mayorkas] has determined that the risk of continued transmission and spread of the virus associated with COVID-19 between the United States and Canada poses an ongoing 'specific threat to human life or national interests,'" the document states.

A similar document was issued for the Mexican border. Both will be published in the Federal Register on Thursday.

"DHS is working closely with counterparts in Mexico and Canada to identify conditions under which restrictions may be eased safely and sustainably," the document notes.

The announcement comes after Canada said Monday it would reopen its border with the United States to fully vaccinated U.S. residents on Aug. 9.

The Canadian government said it felt comfortable reopening the border because of robust vaccination rates.

"With rising vaccination rates and fewer cases in Canada, we can begin to safely ease border measures. A gradual approach to reopening will allow our health authorities to monitor the COVID-19 situation here and abroad," Canadian health minister Patty Hajdu said.