Fleetwood Mac has cancelled the upcoming Australian and New Zealand leg of the band's world tour to allow co-founder and bassist John McVie to seek treatment for cancer.

The classic rock group issued a statement Sunday about the cancellation of 14 upcoming dates.

Mick Fleetwood, Stevie Nicks and Lindsay Buckingham said they hope "fans everywhere will join us in wishing John and his family all the best."

There were no further details about McVie's cancer diagnosis or treatment. Refunds are being offered to all ticket holders for the Australia and New Zealand shows.

British musician McVie, 67, founded the group with Fleetwood in the late 1960s. He was previously married to keyboardist, singer and former bandmate Christine McVie from 1970 to 1978.

The '70s-era rockers, who have seen several lineup changes over the past 40 years, reunited in late 2012 to announce an extensive world tour and plans to attempt writing new music together.

The reunited troupe played Canada and the U.S. earlier this year and recently finished the tour's European leg, where Christine McVie briefly rejoined the group onstage in London in late September. Fleetwood Mac concluded the European dates with a show in Amsterdam on Saturday.

Fleetwood Mac in Concert - Los Angeles

Fleetwood Mac band members (from left) Stevie Nicks, Mick Fleetwood and Lindsey Buckingham said they wish "John and his family all the best." (Chris Pizzello/Invision/Associated Press)

With files from The Associated Press