U.S. Secretary of Defense Chuck Hagel told ABC News he believes the military's ban on transgender soldiers "continually should be reviewed," CNN reported.

"I'm open to those assessments, because again, I go back to the bottom line: Every qualified American who wants to serve our country should have an opportunity, if they fit the qualifications and can do it," Hagel said on Sunday.

In 2010, President Barack Obama signed a bill repealing the military's "Don't Ask, Don't Tell" policy, allowing openly gay and lesbian Americans to serve. However, transgender individuals are still denied. 

"The issue of transgender is bit more complicated because it has a medical component to it," Hagel said. "These issues require medical attention. Austere locations where we put our men and women in many cases don't always provide that kind of opportunity." 

However, a report released earlier this year issued by a commission co-chaired by former U.S. Surgeon General Joycelyn Elders found no "compelling medical rationale" for a ban on transgender soldiers in the military. Additionally, it found that lifting the ban would advance several important military interests, including "enabling commanders to better care for their service members," according to the ACLU.

Following Hagel's comments, the National Center for Transgender Equality said his openness to review the policy was "overdue but very welcome," and called the ban "arbitrary and archaic." 

The advocacy group also claimed thousands of transgender people currently serve in all branches of the military "but are forced to hide who they are or risk losing their careers." 

"If the secretary were able to meet and talk with the trans service members I've met, he'd understand the answer is self-evident," Mara Keisling, the group's executive director, said in a statement. "These are amazing people who serve even though they must hide a basic part of who they are."