North Korea is flouting UN sanctions by exporting coal, iron, steel and other commodities banned under UN sanctions, earning nearly $200 million in revenue last year, a UN report has said.

A UN panel of experts also found evidence of North Korea's ongoing military cooperation with Syria to develop its ballistic missile and chemical weapons programs, and with Myanmar.

North Korea "continued to export almost all the commodities prohibited in the resolutions, generating nearly $200 million in revenue between January and September 2017," said the report by the experts seen by AFP on Friday.

Coal shipments were delivered to China, Malaysia, South Korea, Russia and Vietnam by ship using "a combination of multiple evasion techniques, routes and deceptive tactics," said the report.

The Security Council last year adopted a series of resolutions to tighten and expand exports bans aimed at cutting off revenue to North Korea's military programs.

The United States led the push for tough economic sanctions against North Korea after its sixth nuclear test and a series of ballistic missile launches that indicated the US mainland could soon be within reach of a nuclear strike by Pyongyang.

The panel found that North Korea "is already flouting the most recent resolutions by exploiting global oil supply chains, complicit foreign nationals, offshore company registries, and the international banking system."

Seven ships have been barred from ports worldwide for violating UN sanctions with coal and petroleum transfers, but the experts said much more must be done to confront "these rampant illicit activities."

While sanctions have been significantly broadened, this "expansion of the regime is yet to be matched by the requisite political will" to implement the measures, the experts said.

North Korean diplomats, in particular trade representatives, continue to provide logistical support for arms sales and help organize exchanges for military technicians, it said.