North Korea’s foreign minister Choe Son-hui called a newly-created sanctions monitoring team of her country’s nuclear weapons program ‘illegal and illegitimate’ on Sunday.

Choe Son-hui also warned that the countries that are part of it will have to “pay a high price.”

“I condemn and vehemently reject it as a challenge to international justice and the most blatant violation of North Korea’s sovereignty,” the minister added.

The US, Australia, Canada, South Korea, France, Germany, Japan, Italy, the Netherlands, New Zealand, and the UK together unveiled a new plan to monitor North Korea’s nuclear weapons development on Wednesday.

It came after Russia’s veto at the United Nations Security Council in March triggered the end of monitoring North Korea’s program by a UN panel of experts, alarming Western states and their allies.