(Bloomberg) — Terms of Trade is a daily newsletter that untangles a world embroiled in trade wars. Sign up here. Donald Trump said Boris Johnson’s Brexit deal will make it difficult for the British prime minister to strike a trade deal with the U.S. after the U.K. leaves the European Union.In an interview with Brexit Party Leader Nigel Farage on LBC Radio, the president said the two countries could “do much bigger numbers” if Johnson made a cleaner break with the EU.“We want to do trade with the U.K. and they want to do trade with us,” Trump said. “Under certain aspects of the deal you can’t do it, you can’t trade, we can’t make a trade deal with the U.K. Under certain ways we’re precluded, which is ridiculous by the way.”This is bad news for Johnson, who touts swift and lucrative commercial opportunities with the U.S. as one of Brexit’s biggest prizes. The premier renegotiated the divorce from the EU and is looking to win a Dec. 12 election convincingly enough to get Parliament to finally approve his Brexit deal.On Friday, Johnson’s team hit back. Cabinet minister Robert Jenrick said Trump’s assessment was “not how we see it.” He told BBC radio the Brexit deal enables the U.K. to strike trade agreements with economies around the world “and that includes the United States.”Jenrick also dismissed Trump’s suggestion that the Tories should enter into an election pact with Farage’s Brexit Party. “We are not interested in doing any pacts with the Brexit Party,” he said. Trump’s warning suggests that even if Johnson finally manages to get Brexit through, after more than three agonizing years of political wrangling, it won’t be as straightforward as he had hoped to get that “fantastic” trade deal with the world’s No. 1 economy.LeverageThe president, who prides himself as a deal maker, also indicated the U.S. will be in a strong position in talks. The prime minister “knows how difficult it is,” he said, “he’s looking very much at the United States.”Jeremy Corbyn, leader of the opposition Labour Party, said in a speech Thursday that Johnson wants to deliver a “one-sided Trump trade sell-out” in his rush to reach an agreement with Washington. “His toxic Brexit trade deal with Trump could hand over 500 million pounds a week of NHS money to big drugs corporations,” Corbyn told supporters.Trump denied the claims, saying the U.S. is too busy with its own “health service problems” to get involved in the U.K.“We won’t be involved with that, we’re trying to fix our health service,” Trump said. “It’s not for us to have anything to do with your health-care system, we’re just talking about trade.”‘Bad Places’Trump had harsh words for Corbyn, a socialist who favors higher taxes and wants key utilities back under state control.“Corbyn would be so bad for your country. He’d be so bad, he’d take you in such a bad way,” Trump said. “He’d take you into such bad places.”The Labour leader hit back after the interview, accusing the president of interfering in the election and saying his comments show he wants Johnson in power so U.S. companies can exploit the U.K.’s state-funded healthcare system.“It was Trump who said in June the NHS is ‘on the table’,” Corbyn wrote on Twitter. “And he knows if Labour wins, U.S. corporations won’t get their hands on it. Our NHS is not for sale.”In contrast to his comments about Corbyn, Trump talked warmly about his relationship with Johnson and said the prime minister had confided in him about Brexit.He encouraged Farage’s Brexit Party to make a pact with Johnson for the pre-Christmas election: “He has a lot of respect and like for you,” Trump said. “I wish you two guys could get together, I think it would be a great thing.”The U.S. leader also lavished praise on the royal family and talked at length about his experiences with Queen Elizabeth II, the Prince of Wales and Prince Harry during his visit earlier this year.(Adds Government minister Robert Jenrick comment in fifth paragraph.)–With assistance from Alex Morales and Tim Ross.To contact the reporter on this story: Thomas Penny in London at tpenny@bloomberg.netTo contact the editors responsible for this story: Tim Ross at tross54@bloomberg.net, Flavia Krause-Jackson, Robert JamesonFor more articles like this, please visit us at bloomberg.com©2019 Bloomberg L.P.