Reports claim U.S. President Joe Biden is considering adding legislation requiring COVID-19 tests for all travelers preparing to board a domestic flight .

According to Reuters.com , the Centers for Disease Control and Prevention (CDC) official Dr. Marty Cetron announced Tuesday that the organization was working with the Biden administration regarding the types of tests and where they would be administered if mandatory testing for all domestic flights was enacted.

President Biden has already increased calls to “impose additional public health measures for domestic travel” and consider new requirements for people crossing land borders.

“We realize that there’s been a dramatic evolution and increase in both testing platforms and testing capacity,” Cetron told Reuters. “I think this is a really important part of our toolkit to combat this pandemic.”

On Tuesday, the CDC’s new rules requiring international travelers arriving in the U.S. to show proof of a negative COVID-19 test taken no more than three days before the flight went into effect across the country.

The requirements apply to all passengers two years and older, as well as U.S. citizens returning to America. For those that previously tested positive, they must show documentation of recovery, with the airlines being responsible for verifying the negative test result or post-COVID paperwork.

As a result, some airline officials are concerned the new regulations for international travel and the proposed changes for domestic flights could hurt the already weak demand for air travel.

“The main message to U.S. citizens considering travel abroad remains the same: Seriously reconsider going overseas right now,” Acting Assistant Secretary of State Ian Brownlee told Reuters. “If you’re overseas right now, it’s going to be harder to come home for a while.”