North Korea has not stopped its nuclear and missile weapons programmes and is violating international sanctions, a United Nations (UN) report has found.
The report also found that the secretive state was violating other sanctions, such as through illegal ship-to-ship transfers of oil, and trying to sell weapons abroad.
The report comes just days after it was reported that Pyongyang appeared to be building new ballistic missiles despite recent warming ties with US President Donald Trump's administration and pledges to denuclearise.
Mr Trump met North Korea's Kim Jong-un in Singapore in June, and the two leaders then pledged to work towards denuclearisation, without specifying exactly what this would look like.
However, towards the end of July, North Korea appeared to be dismantling key facilities at its main nuclear test site.
Following the report, US Secretary of State Mike Pompeo warned Russia, China and other countries against any violation of international sanctions on North Korea that could reduce pressure on Pyongyang to abandon its nuclear weapons.
Speaking on the sidelines of an Asian security forum in Singapore, Mr Pompeo said the US has new, credible reports that Russia is violating UN sanctions by allowing joint ventures with North Korean companies and issuing new permits for North Korean guest workers.
He said Washington would take “very seriously” any violations, and called for them to be roundly condemned and reversed.
“If these reports prove accurate, and we have every reason to believe that they are, that would be in violation,” Mr Pompeo said, noting that the UN Security Council had voted unanimously in favour of the sanctions.
“I want to remind every nation that has supported these resolutions that this is a serious issue and something we will discuss with Moscow,” he said.
“We expect the Russians and all countries to abide to the UN Security Council resolutions and enforce sanctions on North Korea.
“Any violation that detracts from the world’s goal of finally, fully denuclearising North Korea would be something that America would take very seriously.”
During a group photo at the ASEAN Regional Forum ministerial meeting later on Saturday, Mr Pompeo went to greet North Korean foreign minister Ri Yong Ho.
They shook hands and briefly exchanged smiles and a few words before Mr Pompeo went back to his original position.
But speaking at the Forum later, Mr Ri hit back at the US for its warning to other countries, condemning it for “raising its voice louder for maintaining the sanctions against” North Korea.
Mr Ri said that while North Korea has “initiated goodwill measures” including a “moratorium on the nuclear test and rocket launch test and dismantling of nuclear test ground”, the US has gone “back to the old, far from its leader’s intention”.