Trump warned that Kim “will regret it fast” if he acts against Guam or any American ally, adding that he hoped Kim fully understood Trump’s words.

It had been known the two sides had discussions to secure the June release of an American university student. But it wasn't known until now that the contacts have continued, or that they have broached matters other than U.S. detainees.

Trump warned on Twitter that “military solutions are now fully in place.”