Donald Trump, the man who sort of penned Art of the Deal, has a tough time making one, according to negotiation experts interviewed by the Huffington Post.

Huffington Post White House correspondent Jennifer Bendery spoke with experts about the transcripts of two phone calls with foreign leaders published last week by the Washington Post. And for a president who promised he’d make the “best deals” ad infinitum, the critiques are less-than-encouraging.

“His skills are few,” professor John Oesch, an associate at the Rotman School of Management at the University of Toronto who focuses on negotiation and decision making, told the Huffington Post.

“This is ill-suited for complex policy decisions that require much more persuasion and problem solving,” international negotiation and mediation researcher Anthony Wanis-St. John said of his call with Mexico’s Enrique Peña Nieto. “It makes Trump look a little venal, a little weak. Not like the president of a great power.”

“He has relied on power (or perceived power), threats, and treating people very poorly to get what he wants,” Oesch added. “Most negotiation scholars agree that power is an unsustainable way to resolve conflict and a poor negotiating technique, unless you want only to take from the other party and not create any value for either side.”

Beyond Trump’s poor negotiating tactics evident in his calls to Nieto and Australian Prime Minister Malcolm Turnbell, the president’s poor grasp of international relations was also on full display. As Bendery notes, in his call to Nieto, Trump offered to send U.S. troops to help fight Mexican drug cartels.

“Anyone who knows anything about the U.S.-Mexico relationship knows that the idea of U.S. troops on Mexican soil is a no-no,”former Mexican ambassador to the U.S. Arturo Sarukhánj told the Huffington Post. “So no one briefed the president and said, ‘This is the type of stuff you can say, this is no-go territory?’ That’s troubling.”