Washington - President Donald Trump is issuing a warning to Iran after its announcement that it has increased its uranium enrichment above the limit set by the nuclear deal that Tehran signed with world powers in 2015.

When asked about Iran on Sunday, Trump told reporters, “Iran better be careful.”

He wouldn’t elaborate on what action the U.S. might take, but said: “Iran’s doing a lot of bad things.”

Trump, who pulled the U.S. out of the nuclear agreement, spoke to reporters at an airport in New Jersey before returning to Washington after a weekend at one of his clubs.

Iran is moving closer toward having weapons-grade levels of uranium, but it’s also calling for a diplomatic solution to a crisis heightening tensions with the U.S.