Kim Yo Jong warned on Friday that “very unkind things await the U.S.” if it does not withdraw its “hostile policy” toward North Korea, justifying the country’s latest long-range missile launch as in line with its “legitimate right to self-defense.”

The statement by the North Korean leader’s powerful sister followed a U.N. Security Council meeting on Thursday, at which the DPRK’s representative put forward similar arguments while the U.S. condemned the test of the Hwasong-18 intercontinental ballistic missile (ICBM) the day before.