Chinese state banks have started suspending transactions through accounts held by North Koreans, making it almost impossible to do business between the two countries, sources familiar with the situation have said.

Kyodo News has confirmed that branch offices of at least three major state banks — the Bank of China, China Construction Bank and Agricultural Bank of China — in the northeastern border city of Yanji have also banned North Koreans from opening accounts.

The Chinese banks have yet to freeze the accounts, meaning that North Koreans can still withdraw money from them, but they are now prevented from making deposits or remittances, the sources said Saturday, speaking on condition of anonymity.