The 81-year-old McCain has been hospitalized at Walter Reed Medical Center in Maryland. Expressing thanks to supporters, McCain's office said Sunday that he "looks forward to returning to Washington in January".
In a statement, Dr. Mark Gilbert, Chief of Neuro-Oncology at the National Institutes of Health, said that McCain responded well to treatment at Walter Reed for a viral infection. "An evaluation of his underlying cancer shows he is responding positively to ongoing treatment".
"They've headed back, but I understand he'll come if we ever needed his help, which hopefully we won't", Trump said.
His office says McCain has returned to Arizona and will undergo physical therapy and rehabilitation at the Mayo Clinic in the state. Republicans secured the support of Sens. Marco Rubio and Tennessee Sen. Soon after, the Senate is expected to take up the measure, which if approved would most likely be signed into law by President Trump, who has been lobbying for its passage.
The Republican senator was admitted into the hospital on Wednesday after missing a third straight day of votes in the Senate.
But McCain's condition has appeared to worsen in recent weeks. McCain also has survived several bouts with melanoma, a risky skin cancer.