If the gift is to secure business this is likely true especially if the business relates to some govt or official of another country. Very strict there - you can't pay a bribe to get business or as part of business development.

However, if you need to pay a "facilitation fee" to exit the country (called routine govt action) that is not about securing business or getting a competitive advantage such as a customs waiver, then paying the fee may be permitted (for a number of reasons).

What I think US folks don't realize is some dept's overseas basically pay their staff through these unofficial fees, they set some rates for service, but nothing goes through treasury and no enabling legislation exists. But they also don't get money from their treasury to operate (or its stolen by folks above them) so that's how they keep operating.