* China Dec imports from North Korea -81.6 pct y/y to $54.34 mln
* China Dec exports to North Korea -23.4 pct y/y to $260 mln
* China 2017 imports from North Korea -33 pct to $1.72 bln
* China 2017 exports to North Korea +8.3 pct to $3.34 bln (Adds milestones, context)
BEIJING, Jan 12 (Reuters) - China's imports from North Korea plunged in December to the lowest level in dollar terms since at least the start of 2014, with trade curbed by U.N. sanctions aimed at persuading North Korea to abandon its ballistic missile and nuclear weapons programmes.
Imports from North Korea slumped 81.6 percent year-on-year to $54.34 million, Huang Songping, Chinese customs spokesman, said in a briefing in Beijing on Friday. That's the smallest monthly value since at least January 2014.
Chinese customs will formally release data for trade with North Korea in the second half of the month, along with a breakdown by product.
The United Nations began imposing sanctions on North Korea in 2006, but tougher measures were invoked in 2017 as tensions flared anew over the country's nuclear and missile programmes.
The penalties that came into force on Sept. 5 last year banned countries from buying coal, iron ore, lead, lead ore and seafood from North Korea.
In November, China imported no iron ore, coal or lead from North Korea, the second full month of the U.N. trade sanctions.
China, the main source of North Korea's fuel, also did not export any gasoline, jet fuel, diesel or fuel oil to its neighbour.
China's exports to North Korea in December declined 23.4 percent from a year earlier to $260 million, Huang told reporters.
Compared with a month earlier, exports fell 9.7 percent.
In November, China stopped exporting oil products to North Korea, after the U.N. Security Council that month imposed new caps on trade with North Korea, including limiting oil product shipments.
For 2017, China's imports from North Korea dropped 33 percent to $1.72 billion, the lowest value in at least four years.
However, exports to the country rose 8.3 percent to $3.34 billion. The value was the highest since 2014.
Non-commodities that China exports to North Korea included electronics, plastic products and garments. (Reporting by Yawen Chen, Stella Qiu and Ryan Woo; Editing by Simon Cameron-Moore)