The European Union imposed additional sanctions on North Korea on Monday over nuclear and ballistic missile tests carried out in defiance of the U.N. Security Council.

The decision, implementing a November UN resolution, comes with North Korea in the international spotlight after the assassination in Kuala Lumpur airport of Kim Jong-nam, the estranged half-brother of leader Kim Jong-un.

The European Council, comprising the EU's 28 member states, said the new measures include restrictions on trade in coal, iron and iron ore, plus a ban on imports of copper, nickel, silver and zinc from North Korea.

The sale of new helicopters and vessels to North Korea was banned, while tighter controls were introduced on the transport, finance and property sectors.

Member states will also curb any teaching, training or scientific links which might benefit North Korea's nuclear and ballistic missile programs, it added.

EU sanctions against North Korea date back to 2006 and are part of international efforts to reverse a nuclear and ballistic missile programs which experts believe is intended to give Pyongyang the capability to hit the US mainland.

A UN report seen by AFP last week said many states were failing to implement sanctions effectively while North Korea got around many of them by using middlemen and front companies, notably in Malaysia and China.

It also warned that North Korea's two nuclear tests and 26 missile launches last year marked "technological milestones in weapons of mass destruction capability and all indications are that this pace will continue."

China, North Korea's main trading partner and ally, suspended all imports of coal from North Korea last week but analysts said this may have been linked to the killing of Kim Jong-nam. who had close ties with Beijing, rather than to the sanctions regime. (AFP)