President Donald Trump vowed to remove the limits barring churches from making political endorsements, telling a gathering of religious leaders in Washington, D.C., on Thursday he would overturn the law that mandates that faith-based organizations restrict their political speech or risk losing their tax-exempt status.

"Among those freedoms is the right to worship according to our own beliefs," he said at the National Prayer Breakfast. "That is why I will get rid of and totally destroy the Johnson Amendment and let our representatives of faith to speak freely and without fear of retribution."

"Freedom of religion is a sacred right, but it's also a right under threat all around us. And the world is under serious, serious threat in so many different ways," he added.

The president's comments recalled a pledge he made on the campaign trail when trying to win the support of a skeptical evangelical community.

In order to overturn the Johnson Amendment, the 1954 rule that prohibits nonprofit organizations from political campaigning, Trump would have to rely on Congress to pass a law changing the tax code. Tax reform is already at the top of congressional Republicans' list of priorities and, given that many are simultaneously in favor of granting more influence to religious organizations and lowering taxes, a proposal for the repeal of the Johnson Amendment would likely be welcomed.

Trump's remarks to religious leaders also touched on the overnight dust-up after his calls to the president of Mexico and Prime Minister Malcolm Turnbull of Australia. The Washington Post reported that the latter call was ended abruptly by Trump, who tweeted that a deal between Turnbull and former President Barack Obama for the U.S. to accept some refugees from Australia was "dumb.".

On Thursday morning, Trump said such tough talk was long overdue.

"When you hear about the tough phone calls, don't worry," he said. "We're being taken advantage of by countries around the world. It's time for us to be a little tough. It's not going to happen anymore."

And he again tweaked his "Apprentice" successor, Arnold Schwarzenegger, over the television ratings for the show.

"We had tremendous success on 'The Apprentice.' When I ran for president, I had to leave the show. That's when I knew for sure I was doing it," he said. "They hired a big movie star Arnold Schwarzenegger to take my place, and we know how that turned out," he added. "The ratings went right down the tubes. It's been a total disaster."

Schwarzenegger hit back, suggesting Trump might like his old gig back if he thought he could do it better.

"Hey, Donald, I have a great idea," the "Celebrity Apprentice" host – and former California governor – said in a video posted to Twitter. "How about we switch jobs?"