The Pentagon will require members of the military to get vaccinated by September 15, 2021. The news came Monday as Amazon initiates a mask mandate, and Canada opens its border to vaccinated United States citizens.

The video above shows Pentagon Spokesman John Kirby discussing the new military requirement.

According to a memo obtained by The Associated Press, the deadline could be moved up if the Pfizer vaccine receives full FDA approval or if infection rates continue to rise. The memo was expected to go out by the end of the day Monday.

“To defend this Nation, we need a healthy and ready force,” Defense Secretary Lloyd Austin said in the memo.

The decision is part of President Joe Biden’s plan to get more federal workers vaccinated.

The news of the military vaccine requirement comes as Amazon’s 900,000 U.S. warehouse workers are required to wear masks indoors now. This, regardless of vaccination status.

Amazon announced the mask mandate Friday. Up until that point, the company had only been requiring unvaccinated workers to wear masks.

Amazon joins Walmart and Target on the list of retailers who have a mandate in place for its workers. While Amazon hasn’t instituted a vaccine requirement for its employees, other companies have. Disney and Walmart announced vaccine mandates for white-collar workers inside offices. Meanwhile, Microsoft, Google and Facebook said they will require proof of vaccination for employees and visitors to their U.S. offices.

In addition, Tyson Foods announced last week it will require all U.S. employees to get vaccinated by November.

Also Monday, Canada lifted restrictions on Americans crossing the border to visit. Canadian officials announced the lifting of restrictions last month. The rest of the world can enter Canada Sept. 7, 2921.

U.S. citizens and legal permanent residents must be both fully vaccinated and test negative for COVID-19 within three days to legally cross into Canada. Travelers also must fill out an application on the arriveCAN app before crossing.

The Canada Border Services Agency won’t say how many people they expect to enter Canada for the reopening.