WASHINGTON — President Trump lavished praise on Monday on Viktor Orban, the authoritarian prime minister of Hungary and one of Europe’s leading nationalists, brushing aside concerns about his rollback of democratic institutions and warming ties with Russia.

“Viktor Orban has done a tremendous job in so many different ways,” Mr. Trump said as he hosted the prime minister at the White House. “Highly respected. Respected all over Europe. Probably like me, a little bit controversial, but that’s O.K. That’s O.K. You’ve done a good job, and you’ve kept your country safe.”

For Mr. Orban, the American president’s embrace was a welcome affirmation, not to mention a striking contrast to the chilly reception he often gets from European leaders who see him as a threat to their vision of a modern, integrated and pluralistic continent. Mr. Orban has vowed to build “an alternative to liberal democracy,” casting himself as a defender of a Christian homeland against Muslim migrants.

Mr. Orban is just the latest of the world’s strongmen to find a warm reception in Mr. Trump’s White House. The president has hosted or praised autocrats from Saudi Arabia, Egypt, the Philippines and Kazakhstan, “fell in love” with North Korea’s Kim Jong-un and upended his entire Syria policy after a phone call with Turkey’s iron-fisted leader, triggering the resignation in protest of his own defense secretary.