Donald Trump returned from his tour of the Middle East Friday with some investment pledges secured in Saudi Arabia and Qatar … but D.L. Hughley is less than impressed with the transactional deals.

TMZ caught up with the comedian on “TMZ Live” Tuesday … and he slammed Trump’s shift in foreign policy, which he says focuses on rewarding whoever “gives [him] a jet or builds [him] a hotel” rather than on shared values.

Notably, Qatar offered an estimated $400 million Boeing 747-8 jet to 47 ahead of his visit, to be used as Air Force One … which Qatar’s prime minister has since denied was an act of bribery. The gift is a violation of the Emoluments Clause of the U.S. Constitution, which forbids American officials from receiving gifts from foreign governments and individuals without Congressional consent — and it’s still unclear whether the plane will be accepted.

D.L. says Trump wouldn’t even be in a position to accept such a lavish gift if he didn’t bulldoze our existing relationships with countries such as Canada and Mexico … forcing him to create ties with new allies.

Harvey pushes back, saying he’s not opposed to the idea of this new “doctrine” — but agrees with D.L. that Trump is the wrong messenger.

Bottom line, the former “The Hughleys” star argues Trump’s refreshed foreign approach is all about serving his best interest first, noting … “[He’s] gonna take off the top and whatever America gets, it gets.”

D.L. also slams Trump’s dramatic approach to tariffs … telling TMZ his back-and-forth actions have been “juvenile” due to his “rudimentary” understanding of how his proposed policies actually work.

He doesn’t back down, and even goes on to insist America’s reputation is “up for sale” due to Trump’s behavior … even calling him a “carnival barker.”