Washington, Jul 20 (IANS): US Senator and former Republican presidential candidate John McCain was diagnosed with a brain tumour, his office has said.

On July 14, the 80-year-old senator underwent an operation at Mayo Clinic Hospital in Phoenix to remove a blood clot from above his left eye, which has been known to be associated with a primary brain tumour.

"The senator's doctors say that he is recovering from his surgery 'amazingly well' and that his underlying health is excellent," the Mayo Clinic said in a joint statement with the senator's office on Wednesday.

The senator and his family were reviewing further treatment options including a combination of chemotherapy and radiation, the note added.

McCain's health condition has forced Republicans to postpone voting on the new health bill, scheduled this week in the Senate, Efe news reported.

McCain has served as senator for Arizona since 1987. He lost the presidential elections against Barack Obama in 2008.

He had fought in the Vietnam War.