MOSCOW, August 26. /TASS/. US Senator John McCain, who had earlier been diagnosed with brain cancer, passed away on Saturday at the age of 81.

The senator died at 16:28 local time (23:28 Moscow time) on August 25, 2018, his office announced.

"Senator John Sidney McCain III died at 4:28 p.m. on August 25, 2018. With the senator when he passed were his wife Cindy and their family," his office said in a statement. "At his death, he had served the United States of America faithfully for 60 years."

His wife Cindy said in a Twitter post: "He passed the way he lived, on his own terms, surrounded by the people he loved, in the the place he loved best."

McCain’s diagnosis was made public on July 19, 2017. The tumor was discovered during a three-hour-long surgery on July 14, 2017, to remove a five-centimeter blood clout from above his left eye.

A doctor who performed the surgery told CNN that the senator had an aggressive glioblastoma and it was removed during the surgery.

US President Donald Trump expressed his condolences McCain’s family in a Twitter statement.

"My deepest sympathies and respect go out to the family of Senator John McCain. Our hearts and prayers are with you!" he said.

McCain was one of the staunchest supporters of anti-Russian sanctions and was known for his harsh criticism of Moscow.