A Japanese government spokesman on Sunday welcomed China’s announcement to suspend all North Korean coal imports until the end of this year as part of strengthened sanctions against Pyongyang in response to its nuclear and missile development programs.

“The North Korean threat has increased, including its missile development. China’s decision is a welcome development,” Deputy Chief Cabinet Secretary Koichi Hagiuda told a TV program Sunday morning.

China’s Commerce Ministry said Saturday that the suspension of coal imports was in accordance with U.N. Security Council Resolution 2321, adopted in November 2016 following North Korea’s fifth nuclear test, which was carried out in September the same year.

The resolution particularly targeted coal, North Korea’s biggest export, much of which is delivered to China.

“By increasing pressure, we have to help North Korea realize that silly acts will further isolate the country in the international community,” Hagiuda said, noting that Japan has urged the North to refrain from nuclear and missile development through pressure and dialogue.