Sen. John McCain to return to D.C. in January, friend Sen. Lindsey Graham says

Ailing Sen. John McCain will return to Washington, D.C., in January, one of his closest friends said Sunday.

"Senator McCain is in rehab. He's coming back in January, (and) we need his voice now more than ever," Sen. Lindsey Graham said on CBS' "Face the Nation" in response to a question about the 81-year-old Arizona Republican's condition.

McCain is battling an aggressive form of brain cancer called glioblastoma. He recently was hospitalized in Bethesda, Maryland, for a viral infection and other side effects of his ongoing chemotherapy and radiation treatment.

Graham, R-South Carolina, did not elaborate on his response, which echoed previous comments made by Senate Majority Leader Mitch McConnell, R-Kentucky, and Arizona Gov. Doug Ducey.

McCain's office has not issued an official update on his health since Dec. 17, when it confirmed McCain had been discharged from Walter Reed National Military Medical Center and returned to Arizona for physical therapy and rehabilitation at Mayo Clinic.

McCain's office said at the time that the senator "looks forward to returning to Washington in January."

Mark Gilbert, chief of neuro-oncology at the National Institutes of Health's National Cancer Institute, said in a written statement released at the same time that McCain "has responded well to treatment he received at Walter Reed Medical Center for a viral infection and continues to improve."

"An evaluation of his underlying cancer shows he is responding positively to ongoing treatment,” Gilbert said.

Nowicki is The Republic's national political reporter. Follow him on Twitter @dannowicki.

READ MORE:

Meghan McCain: Her father, John McCain, is 'doing good'

McCain and Flake's 2017: A sad prognosis, a crazed gunman and a dramatic decision

Poll: John McCain is the fourth-most admired man in the world

Jeff Flake talks with John McCain, says he 'sounded good'