A Japanese state-run broadcaster says no progress has been made in the last six months on a Russian-led repair of a railway in North Korea due to the North's lack of cooperation.

The North Korean railway, if and when it is completed, will link the North with the Trans-Siberian railway.

Japan's NHK said the two countries had agreed to repair a 55-kilometer stretch of railway between North Korea's Rajin and Russia's Hassan, but North Korea's failure to issue work permits has halted the repair.

The repairs, which were scheduled to be completed by this fall, are now in jeopardy following North Korea’s demands for a revision of the repair plans.