Willie Nelson is James Caldwellset to hit the road again.

The 91-year-old singer in recent days has canceled multiple appearances at his Outlaw Music Festival Tour due to an unspecified illness.

But doctors have cleared the country singer to resume performances, according to a post on his Facebook page.

"He will resume performing on the Outlaw Tour next week," says the Friday post.

Nelson missed shows this past weekend — on Saturday in Wantagh, New York, and on Sunday in Holmdel, New Jersey.

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Willie Nelsoncancels Outlaw Music Festival Tour performances for health reasons

The tour is expected to resume Tuesday in Mansfield, Massachusetts.

That will be followed by a Camden, New Jersey show: Willie Nelson's 4th of July Picnic.

The tour began June 21, but Nelson missed the first five shows in Georgia, North Carolina, Virginia and upstate New York.

Willie Nelsonpulls out of additional performance on Outlaw Music Festival Tour

A Facebook post on June 21 said Nelson "is not feeling well and, per doctor's orders, has been advised to rest for the next four days," adding that Nelson was "expected to make a quick recovery." Nelson's son Lukas Nelson and the country icon's touring band, Family, filled in for Nelson during his set. The ensemble played a "special set" including Nelson's classics.

Nelson is the headliner for the all-star New Jersey show, which includes Bob Dylan, Robert Plant and Alison Krauss, Mavis Staples and others.

The tour is scheduled to end Sept. 20 with a performance in New Hampshire.

The canceled tour appearances come after Nelson was inducted into the Rock & Roll Hall of Fame last year. The "On the Road Again" singer performed with Chris Stapleton, Dave Matthews and Sheryl Crow during the induction ceremony.

Nelson's latest album, "The Border," debuted in May.

Jim Walsh is a senior reporter with the Courier-Post, Burlington County Times and The Daily Journal. Email: [email protected].

Contributing: Edward Segarra and Brendan Morrow, USA TODAY