Speaking at a campaign rally in Lansing, Michigan, on Tuesday night, Mr Trump claimed world leaders praise his administration for doing “the most incredible job”.
But he said he had to turn down requests from “many of these nations who are not that friendly” to buy American military equipment.
“A lot of times, ‘cause you know, I’ve become friendly with many of the presidents and prime ministers, kings and queens, dictators - I must tell you, dictators - but I’ve become friendly with a lot of them,” he told supporters, some of whom donned MAGA face masks.
“They say two things: it’s incredible what you’ve done with the economy, they always say that. They always say it, no matter what. They say we have done the most incredible job, and they always start off by congratulating me.
“The next question is that they wanna buy our military equipment because we make the best equipment anywhere in the world, and sadly, with many of these nations who are not that friendly, we have to say no. Does that make sense?” he adds.
It comes after the president boasted on Monday that foreign authoritarian leaders prefer working with him compared to his presidential opponent Joe Biden.
He claimed that one foreign leader told him they wanted him to win the election on 3 November because “we don’t want to deal with someone who sleeps all the time”.
Mr Trump said during a rally in Allentown, Pennsylvania: “The only thing I can tell you for sure, President Xi from China, President Putin from Russia, Kim Jong-un from North Korea, and I could name 40 others - they’re sharp as a tack, they don’t want to deal with Sleepy Joe.”
Former president Barack Obama, who has been campaigning for Mr Biden, took aim at Mr Trump’s words and questioned why he would brag about authoritarian leaders wanting him to win.
In Orlando on Tuesday, Mr Obama said: “Our current president, he whines that ’60 Minutes’ is too tough. You think he’s going to stand up to dictators? He thinks Lesley Stahl’s a bully.
“Just yesterday, he said that Putin of Russia, Xi of China, and Kim Jong-un of North Korea want him to win. We know! We know because you’ve been giving them whatever they want for the last four years! Of course they want you to win!
“That’s not a good thing. You shouldn’t brag about the fact that some of our greatest adversaries think they’d be better off with you in office. Of course they do. What does that say about you? Think about that. Why are you bragging about that? C’mon. That doesn’t make any sense.”