"China will temporarily stop its imports of coal from North Korea for the rest of this year."

China says it will suspend all imports of coal from North Korea for the rest of the year, depriving the country of a crucial source of foreign exchange following its latest missile test.

The suspension, which implements existing UN sanctions over North Korea's nuclear programmes, will start on February 19 and remain in force until the end of the year, China's commerce ministry said in a statement posted on its website on Saturday.

China "will temporarily stop its imports of coal from North Korea for the rest of this year" including coal for which customs applications have been made but not yet processed, it said.The decision came after North Korea's February 11 missile test, as tensions escalate over the reclusive state's defiance of UN resolutions.

China had traditionally ensured that UN Security Council resolutions on sanctions against North Korea included humanitarian exemptions, and had continued to purchase huge amounts of North Korean coal - worth $101m in October alone.

Einar Tangen, a Beijing-based analyst, says China's move would have a massive impact on North Korea's economy.

"Coal represents one-third of North Korea's total exports ... The entire GDP of North Korea was about $17bn and now $1bn has effectively disappeared. This is biting into the very lifeblood of the administration," he told Al Jazeera.

China, a long-time main ally and neighbour of North Korea, appeared to be moving towards improved ties with South Korea after its political opposition gained popularity following President Park Geun-hye's impeachment, Tangen said.