Chinese banks in the northern border city of Dandong have suspended the transfer of the yuan currency to North Korean banks, Chinese financial sector officials told Yonhap News Agency on Wednesday. 

The move comes as the U.N. Security Council is set to vote on new sanctions against North Korea's fourth nuclear test and rocket launch this year. 

Employees of the Dandong branch offices of China's top four state-owned banks, including Agricultural Bank of China and Industrial and Commercial Bank of China, as well as six commercial banks such as China Merchants Bank, told Yonhap that the suspension came after "orders" from their headquarters. 

Since North Korea's third nuclear test in 2013, the Dandong branches of the Chinese banks have halted the transfer of U.S. dollars to North Korean banks. 

An employee of the Dandong branch of the Agricultural Bank of China said the order came down after North Korea's fourth nuclear test in January. 

Dandong is a border city between North Korea and China and a main conduit of bilateral trade between the two neighboring countries. (Yonhap)