Story highlights McCain was diagnosed with a brain tumor in July

A specific date for his return has not yet been determined

Washington (CNN) Arizona Republican Sen. John McCain plans to return to Washington soon, sources close to the senator tell CNN.

In December, it was announced that McCain would return home to Arizona for the remainder of the month to recover from a hospitalization as a result of cancer treatments. During his recovery, he missed the Senate vote on a finalized version of the GOP-backed tax plan.

McCain is feeling better following his recovery in Arizona, the sources said.

The senator suffers from a type of brain tumor called a glioblastoma. He was diagnosed with the tumor following surgery to remove a blood clot in July.