However, he commented on the trade imbalances between the two countries, saying Ireland took advantage of the US by lowering its corporate tax rates in the early 2000s.
That has reportedly driven over 1,000 American businesses to move across the Atlantic since then.
Talking to Micheál Martin, Trump said he respects what Ireland had done, but past US leaders had failed.
"We had stupid leaders, we had leaders who didn't have a clue," he said.