Los Angeles (CNN) -- The final international leg of Glen Campbell's "Goodbye Tour" in Australia and New Zealand has been canceled because the long flight would have been too taxing for him, his representative said Wednesday.
The Country Music Hall of Famer began the world tour last year after he went public with his Alzheimer's diagnosis.
Campbell, 76, will perform the final shows on his U.S. tour, including six more shows this month and two in October, his rep said.
"As August approaches Glen realizes that he cannot handle the extremely long travel that is required from Los Angeles to New Zealand and Australia," his rep said. "He has always loved performing in these countries and apologizes to his fans Down Under."
Last fall, Campbell released his final album, "Ghost on the Canvas," then hit the road on for his farewell tour.
Despite his illness, Campbell delivers a smooth performance. He uses teleprompters at the foot of the stage help him with lyrics to the songs he's sung for decades.
His family surrounds him on the stage to help in those rare moments when he becomes disoriented.
"He looks at me sometimes if he is confused, and I just smile at him," said daughter Ashley, who stands nearby playing keyboards, banjo and violin. "I just try to make him feel like he is surrounded by people that love him on stage."
Campbell, who won five Grammys during his recording career, was given a Grammy Lifetime Achievement Award this year. He also performed in the live Grammys telecast in February.
Campbell began his recording career as a Los Angeles studio musician in the late 1950s, lending his talents to many hits. He became part of the renowned "Wrecking Crew" of musicians.
Campbell joined the Beach Boys as a tour fill-in for Brian Wilson in 1964 and 1965. He played on the group's "Pet Sounds" studio album in 1966.
He released his first solo record in 1962, but his career skyrocketed with the 1967 release of two songs that made music history. "Gentle on My Mind" was awarded two Grammys in the country category, while "By the Time I Get to Phoenix" was honored with two pop Grammys.
Other major hits followed, including "Wichita Lineman" in 1968 and "Galveston" a year later. He hit the top of the country chart again in 1975 with "Rhinestone Cowboy" and with "Southern Nights" in 1977.
John Wayne was so impressed with the Arkansas native that he cast him in his 1969 big-screen classic "True Grit." Campbell's acting earned him a Golden Globe nomination for "Most Promising Newcomer."
Campbell became a television star when he hosted a summer replacement show on CBS in 1968, which led to "The Glen Campbell Goodtime Hour," debuting in May 1969.
CNN's Denise Quan contributed to this report.