A sign marking North Korea's border with China. Photo: Wikipedia

Branches of each of China’s top five banks said they have been instructed to stop opening new accounts for North Korean individuals or companies, reports the Financial Times.

Several of the banks, which had reportedly received notice as early as last January, have also begun “cleaning out” existing accounts by prohibiting new deposits.

While the ban goes further than UN sanctions, and is a sign that calls within Beijing for putting more pressure on Pyongyang are being heard, it is unclear how effective the restrictions will be.

“We always use Chinese citizens living in North Korea as intermediaries when doing business,” one groceries trader in Dandong was quoted by the Financial Times as saying. “There’d be no reason to freeze Chinese nationals’ accounts, unless they’re sanctioning individuals,” he added.