A contractual problem has halted a ferry plying a route between Russia and North Korea.

The Sputnik news agency cited Vladimir Baranov, director general of the operation, as saying that the run between Vladivostok and Rason had been suspended due to the absence of a contract agreement.

"At the moment, the work of the motor ship is suspended, and it stays in Rason in North Korea. The timetable for September has not been agreed with the Vladivostok harbour station so far," he added.

The service was launched in May, but global tensions have continued to rise as North Korea's nuclear weapons programme threatens to draw the US and China into a wider regional dispute.