"You know, when they say that China spies on us, I say you're right, and we spy on them too," Trump told reporters aboard Air Force One a day after The Wall Street Journal reported Beijing's intelligence sharing.
"That's what we do. They basically do what we do," Trump said.
The incident could deepen tensions between Washington and Beijing ahead of a planned state visit by Chinese President Xi Jinping to the White House on September 24.
On July 17, Iran launched missile strikes on the Muwaffaq Salti Air Base in Jordan, which houses US forces. Three US Army soldiers were killed.
Unnamed American officials cited in the Journal's reporting did not name the Chinese entities involved, and did not suggest that Beijing was directly to blame.
Chinese officials asked for proof of the transfer of satellite imagery when prodded by the US officials, and refused to acknowledge that Chinese companies were involved in providing Tehran with satellite images, the Journal reported late Friday.
Trump has warned Beijing not to sell weapons to Iran, and in May, Washington sanctioned three China-based satellite companies for enabling Iran's military operations.
China is a top economic partner of Iran, buying much of its oil output, and also an important diplomatic backer.
Still, Trump said of Xi on Sunday that "he's behaved reasonably well, and we behave reasonably well."
Asked if he would ever allow Chinese cars to be sold in the United States, Trump said "I haven't. I'm the one that kept them out. The tariffs kept them out."
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