The experts warned time was running out to curb the reclusive state’s ballistic and nuclear weapons programs, the Wall Street Journal reported.
They allegedly blamed China, Russia and other countries for helping Pyongyang dodge UN restrictions, which severely cut the North’s ability to export a wide range of goods it relied on for income.
However, US Secretary of State Rex Tillerson said in January Washington had evidence that North Korea was beginning to feel real damage from the sanctions placed against Pyongyang.
Earlier, the UN Security Council has introduced multiple sanctions against North Korea in order to impede the development of the country’s nuclear program.
Tensions have escalated on the Korean Peninsula in recent months after the United States and North Korea traded threats and insults following Pyongyang’s nuclear and ballistic missile tests.