North Korea has been selling weapons to the governments of Syria and Myanmar, and has been exporting banned materials such as coal, iron, and steel, a United Nations report has found.

According to the report released on Friday, Pyongyang has been assisting Syrian President Bashar al-Assad's government in developing its nuclear weapons programme, and has provided Myanmar's army with ballistic missiles.

North Korea "continued to export almost all the commodities prohibited in the resolutions, generating nearly $200m in revenue between January and September 2017," the report read, according to the AFP news agency which has seen a copy.

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

Last year, the UN Security Council adopted a series of resolutions aimed at restricting exports, with the objective of cutting off revenue to North Korea's military programme.

The United States has pushed for tough sanctions against North Korea in response to its missile tests, and together with the UNSC vowed to prevent Pyongyang from furthering its nuclear programme.

According to the report and the UN panel of experts, seven ships have been prevented from entering ports worldwide for violating UN sanctions with coal and petroleum transfers.

They said that much more needed to be done to challenge such "these rampant illicit activities".

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", the panel noted.

Countries accused of crimes against humanity

Syria and Myanmar have previously been accused of carrying out acts that amount to crimes against humanity.

The report comes as the United States is investigating reports of chlorine gas being used against civilians in Syria's besieged Eastern Ghouta.

The North Korean company cooperating with the two governments - KOMID - is on a UN sanctions blacklist, according to the report.

The panel revealed that more than 40 unreported shipments from North Korea between 2012 and 2017 went to front companies for Syria's Scientific Studies Research Council, a key institute for Syria's chemical programme.

The investigations also reveal "substantial new evidence" concerning Pyongyang's military cooperation with Damascus, including at least three visits by North Korean technicians to Syria in 2016, involving the "transfer of special resistance valves and thermometers known for use in chemical weapons programmes".

According to a member state that remained unidentified in the report, North Korean "technicians continue to operate at chemical weapons and missile facilities at Barzei, Adra and Hama."

Syria denied the presence of North Korean technicians in its territory, claiming that the only experts it was hosting from the country were involved in sport.

A member state, which also remained unnamed, notified the panel that Myanmar had received "ballistic missile systems from [North Korea] in addition to a range of conventional weapons, including multiple rocket launches and surface-to-air missiles".

North Korean diplomats in trade particularly continue to provide logistical support for arms sales and help organise exchanges for military technicians.

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

The panel added that this year offered a "critical window of opportunity before a potential miscalculation with disastrous implications for international peace and security".