Syrian President Bashar al-Assad's regime has repeatedly denied claims that it uses chemical weapons. Medical aid organizations, however, say they have routinely treated victims of chemical attacks and blame government forces, as the country's war nears its seventh anniversary. The US and other countries have made the same accusations against the Assad government.

The report says the Syrian government specifically denied the accusations there were missile experts from North Korea inside the country, saying instead they were sports trainers.

A UN spokesman, who had not seen the report, reminded member states of the sanctions restricting trade with North Korea while pointing out the dangers of aiding Syria's chemical capabilities.

"The last thing we need in Syria is more weapons ... God forbid chemical weapons," he said.

A spokesperson for South Korea's Ministry of Foreign Affairs, said they were closely watching North Korea's attempts to evade UN sanctions. "We are racing to intercept North Korea's violation of UN resolution and putting all diplomatic efforts with cooperation with the international community," she said.

A spokesperson for Japan's Ministry of Foreign Affairs said the government was aware of the report and declined to comment beyond reiterating its commitment to enforcing sanctions. A US State Department official also declined to comment on the UN report because of its confidential nature.

The official said that since 2006, "the Security Council has required the DPRK‎ (North Korea) to cease export of arms and related material as well as items relevant to nuclear, ballistic missiles and other weapons of mass destruction-related programs and to fully abandon all weapons of mass destruction programs."

The UN reports on North Korea are kept secret as they are reviewed by the UN Security Council. They are later declared official and made public. The diplomat who spoke to CNN said that they expect this report to be released on March 16.

Despite numerous rounds of international sanctions, North Korea exported almost all the commodities that had been prohibited in the resolutions between January and September of last year, the report indicates.

Among its coal export recipients was China, the report said. China has consistently denied breaching sanctions.

Correction: This story has been updated to note that the UN reports on North Korea are ultimately made public and correctly state the name of the spokesperson for South Korea's Ministry of Foreign Affairs.