China banned all coal imports from North Korea starting Sunday, a move that steps up a prohibition Beijing enacted last year and comes as recent actions by Pyongyang test relations between the two allies, according to The Wall Street Journal. The temporary ban, which the Ministry of Commerce said would remain through the end of this year, follows North Korea’s launch of a ballistic missile into the Sea of Japan this month, in defiance of international sanctions. The freeze includes all incoming North Korean coal shipments that importers had applied for but not yet received official approval, the Chinese ministry said. Beijing in December halted most coal imports from North Korea in support of United Nations sanctions to deter Pyongyang’s nuclear ambitions, but left open imports for “humanitarian exemptions”—a loophole meant to help sustain North Korea’s economy.