Rockers Train have pulled out of performing at an upcoming Boy Scouts of America Jamboree unless the organisation's ban on openly gay and transgender leaders is lifted.

The trio signed up to perform at the event in July (13), but singer Pat Monahan and his bandmates are now boycotting the gig over Boy Scout officials' anti-gay stance.

A statement announcing the decision not to play the Jamboree reads: "When we booked this show for the Boy Scouts of America, we were not aware of any policy barring openly gay people from participation within the organization.

"Train strongly opposes any kind of policy that questions the equality of any American citizen. We have always seen the BSA as a great and noble organization. We look forward to participating in the Jamboree this summer, as long as they make the right decision before then."

Train were scheduled to play the event in West Virginia with Carly Rae Jepsen.