BEIJING (Reuters) - China's suspension of imports of North Korean coal shows it is sincere about implementing UN Security Council resolutions punishing North Korea over its nuclear weapons and missile programmes, it said on Tuesday (Feb 21).

China's Commerce Ministry said on Saturday it would ban coal imports until the end of this year. The ban came about a week after North Korea tested an intermediate-range ballistic missile in its first direct challenge to the international community since U.S. President Donald Trump took office.

Trump's administration has said China should do more to put pressure on North Korea.

All members of the United Nations had a duty to carry out Security Council resolutions, Foreign Ministry spokesman Geng Shuang told a regular press briefing.

"This move reflects China's responsible attitude on the Korean nuclear issue and its sincerity in implementing U.N. Security Council resolutions," Geng said, referring to the ban.

South Korea's Yonhap news agency reported last week that a shipment of North Korean coal worth about US$1 million was rejected at Wenzhou port on China's eastern coast.

China announced in April last year that it would ban North Korean coal imports in order to comply with sanctions imposed by the United Nations and aimed at starving the country of funds for its nuclear and ballistic missile programmes.

But it made exceptions for deliveries intended for "the people's wellbeing" and not connected to the nuclear or missile programmes.

Despite the restrictions, North Korea remained China's fourth biggest supplier of coal last year, with non-lignite imports reaching 22.48 million tonnes, up 14.5 per cent compared with 2015.

North Korea, which regularly threatens to destroy South Korea and its main ally, the United States, conducted more than 20 missile tests last year, as well as two nuclear tests, in defiance of U.N. resolutions and sanctions.