Japan has extended economic sanctions on North Korea, citing a lack of progress in a row over Japanese nationals abducted by Pyongyang.

The measures - which ban imports from North Korea and visits by its ships - will continue for another six months.

A top official said Japan was seeking advances on both the abduction and nuclear issues.

The move comes exactly a year after North Korea carried out its first nuclear test, on 9 October 2006.

Since then, Pyongyang has agreed to end its nuclear programme in return for millions of dollars worth of aid.

It has closed its main Yongbyon reactor and last week committed to a timetable for disclosing and dismantling all its nuclear facilities by the end of the year.

Later this week, a US-led team of experts are due to visit North Korea, where they will begin supervising the process of dismantling its nuclear installations.

'No progress'

Japan is one of the five countries involved in the nuclear deal with North Korea.


JAPAN'S MISSING
Abductee Megumi Yokota, who North Korea says is dead

But a major sticking point in the bilateral relationship has been the issue of Japanese citizens abducted by Pyongyang in the late 1970s and early 1980s to train spies.

"We saw the need to extend the sanctions because there has been no progress over the abduction issue," Chief Cabinet Secretary Nobutaka Machimura told journalists after the move was agreed at a Cabinet meeting.

North Korea admitted in 2002 that it had kidnapped 13 Japanese nationals. It has returned five of them and says the remaining eight are dead. It says the issue has now been resolved.

But Japan wants concrete proof of the deaths and believes that several more of its citizens were taken. There is huge public concern over the issue in Japan.

Talks in Mongolia last month aimed at resolving the dispute came to nothing.

The abduction row was not the only factor behind the decision, Mr Machimura said.

"We also took into comprehensive consideration the overall situation involving North Korea, including the nuclear issue," he said.

A foreign ministry official told the Associated Press news agency that Japan wanted to see concrete steps from Pyongyang towards disabling its nuclear programme.

The sanctions - imposed last October after North Korea's nuclear test - prevent visits by the Mangyongbong-92 ferry, the only direct link between the two countries, and ban imports from the impoverished nation.

They have now been extended until 13 April, officials said. The decision needs the endorsement of parliament, but the opposition have already agreed to the step.