India, Feb. 2 -- Iran's supreme leader warned Sunday that any attack by the United States would spark a "regional war" in the Mideast, further escalating tensions as President Donald Trump has threatened to militarily strike the Islamic Republic. The comments from the 86-year-old Ayatollah Ali Khamenei are the most-direct threat he's made so far as the aircraft carrier USS Abraham Lincoln and associated American warships are in the Arabian Sea, sent by Trump there after Tehran's bloody crackdown on nationwide protests.

It remains unclear whether Trump will use force. He's repeatedly said Iran wants to negotiate and has brought up Tehran's nuclear program as another issue he wants to see resolved. But Khamenei also referred to the nationw...