Japan on Friday extended sweeping sanctions against North Korea for another six months, saying the communist state has not shown progress in impasses over its nuclear drive and abductions of Japanese, reports AFP.

The sanctions-which ban all imports from cash-strapped North Korea including money-making goods such as clams, crabs and high-end matsutake mushrooms-were set to expire on Sunday.

Foreign Minister Masahiko Komura said Japan was ready to lift the ban at anytime if North Korea makes progress on the issues. "The extension is for another six months," he told reporters.

"But Japan may end part or all of the sanctions even during that period if North Korea takes concrete, positive actions over the abduction, nuclear and missile issues." Japan has tense relations with North Korea in part due to the communist regime''s kidnapping of Japanese civilians in the 1970s and 1980s to train its spies.

North Korea returned five abductees in 2002 and says the case is closed. Japan insists that more are alive and being kept under wraps. Japan imposed the sanctions, which also include a ban on all port calls by North Korean ships, after the communist state tested an atom bomb in Oct 2006.

North Korea last year signed a six-nation deal to abandon its nuclear weapons in exchange for badly needed energy and economic aid, security guarantees and diplomatic benefits.

But implementation of the pact has been slow, with North Korea missing a deadline to declare all of its nuclear programmes by the end of last year amid a dispute with the US.

The six-nation deal involves the two Koreas, Japan, China, Russia and the US. Japan has been the most critical nation in the deal, refusing to contribute aid due to the abductions, an emotionally charged issue at home.

South Korea''s new conservative president, Lee Myung-Bak, has also taken a harder line since taking office in Feb, infuriating the North.