North Korea dismantles nuclear test site in May. (Picture: PA)
A confidential United Nations report has accused North Korea of continuing to develop nuclear and missile programs in violation of international sanctions.
A summary of the report by experts, which was sent to the Security Council on Friday night, said the country is also violating sanctions by transferring coal at sea, illicitly transferring oil and flouting both an arms embargo and financial sanctions.
The panel of experts said North Korea attempted to sell small arms, light weapons and other military equipment via foreign intermediaries in Yemen, Libya and Sudan.
The report also said North Korea has continued military co-operation with Syria, in breach of sanctions.
The Security Council first imposed sanctions on North Korea after its first nuclear test in 2006 and has made them increasingly tougher in response to further nuclear tests.
US and North Korean officials have traded polite words and then barbs in the latest round of diplomacy, leaving efforts to rid Pyongyang of its nuclear weapons at an uncertain point.
At a security conference in Singapore, US Secretary of State Mike Pompeo accused North Korea and countries including Russia of continuing to violate UN sanctions aimed at pressing the North to give up its nuclear arsenal.
But at the same time, he oversaw the handover of a letter to North Korean leader Kim Jong Un from US President Donald Trump and exchanged pleasantries with the North's foreign minister Ri Yong Ho.
Mr Ri, meanwhile, greeted Mr Pompeo with a smile and posed for photos - but then delivered a scathing attack on the Trump administration for approaching the negotiation poorly by insisting on sanctions enforcement.
Mr Ri said North Korea would not be forced into acting unilaterally, and demanded that the US undertakes "confidence building" measures if the negotiation is to be successful.
After Mr Pompeo warned once again that no sanctions would be lifted until North Korea fully and finally denuclearises, Mr Ri told the annual ASEAN Regional Forum that the North will not be bullied into concessions.
"Confidence is not a sentiment to be cultivated overnight," he said. "In order to build full confidence between the DPRK and the US, it is essential for both sides to take simultaneous actions and phased steps to do what is possible one after another.
"Only when the US ensures that we feel comfortable with and come close to it, will we be able to open our minds to the US and show it in action."
The US has previously dismissed calls for a phased approach, insisting that sanctions be maintained until the North delivers on its commitments but suggesting some other steps may be possible.
Mr Ri, though, appeared unmoved and accused elements of the US government of going against Mr Trump's wishes by taking a hard line on sanctions.
"What is alarming, however, is the insistent moves manifested within the US to go back to the old, far from its leader's intention," he said.