President Trump on Wednesday night offered support for Sen. John McCain who was diagnosed with brain cancer.

"Senator John McCain has always been a fighter," Trump said in a statement. "Melania and I send our thoughts and prayers to Senator McCain, Cindy, and their entire family. Get well soon."

McCain, R-Ariz., recently received an operation to remove a blood clot from above his left eye. Tissue extracted during the procedure, described as successful, proved to be cancerous, according to the Mayo Clinic in Phoenix, where the senator is being treated. McCain's office shared the hospital's statement Wednesday evening. Treatment options, including chemotherapy, are being reviewed.

An additional statement, from McCain's Senate office, said there was no timetable for the 80-year-old's return to work in Washington.