File photo taken on July 25, 2017 shows U.S. Senator John McCain exiting the Capitol in Washington D.C., the United States. U.S. Senator John McCain, a two-time contender for the U.S. presidency, died at his home in the state of Arizona on Saturday, his office said in a statement. He was 81. (Xinhua/Ting Shen)

WASHINGTON, Aug. 25 (Xinhua) -- U.S. Senator John McCain, a two-time contender for the U.S. presidency, died at his home in the state of Arizona on Saturday, his office said in a statement. He was 81.

"Senator John Sidney McCain III died at 4:28 p.m. (2328 GMT) on August 25, 2018. With the senator when he passed were his wife Cindy and their family," the statement said.

McCain had suffered from a malignant brain tumor and had been treated periodically with radiation and chemotherapy since its discovery in 2017.

"My deepest sympathies and respect go out to the family of Senator John McCain. Our hearts and prayers are with you!" U.S. President Donald Trump tweeted Saturday night.

McCain was elected to the U.S. House of Representatives in 1982 before entering the Senate in 1987. He won reelection five times, with the last one in 2016. He became chairman of the Senate Armed Services Committee in 2015.

In 2000, McCain entered the race of the GOP nomination for the U.S. presidency but lost to George W. Bush, then governor of Texas who later won the general election and became the country's 43rd president.

Eight years later, McCain secured his party's nomination for the presidency but was defeated by then Democratic Party nominee Barack Obama.

The son and grandson of Navy admirals, McCain was born in 1936 in Panama and entered the U.S. Naval Academy at Annapolis, in the state of Maryland, and became a fighter pilot after graduation.

In 1967, his aircraft was shot down during a bombing mission over Vietnam, where he was held as a prisoner of war for five and a half years.