When bonds to be issued by or on behalf of a public body have been authorized by an election or other method provided by law, and where it is expected that all or any part of such bonds will be sold at such time that principal or interest on such bonds will become due before the proceeds of a tax or assessment levied after such sale would be available to pay such principal or interest, the governing body, at the time of fixing the annual tax or assessment levy, may levy a tax or assessment, as the case may be, in an amount clearly sufficient to pay that portion of the principal of and interest on said bonds which it is expected will become due before the proceeds of the next succeeding tax or assessment levy will be available.