The US has rallied the international community to sever ties with the North to further isolate the regime and force it to give up its nuclear weapons and ballistic missile programs.

The UN Security Council unanimously adopted two sanctions resolutions against Pyongyang after its long-range missile tests in July and sixth nuclear test in September.

A growing number of countries have also expelled North Korean diplomats and scaled back economic ties.

"This is something that is a key part of Secretary (of State Rex) Tillerson's pressure campaign," Nauert said.

Thousands of North Koreans reportedly work in the Middle East to earn foreign currency to fund the regime's weapons programs. (Yonhap)