Vienna, Seoul: North Korea has reportedly deployed more than 10 missiles on its west coast for what appears to be an imminent launch, and diplomats said on Thursday the North has barred UN monitoring throughout its nuclear complex.

Those potentially destabilising moves came amid reports that the US has offered to remove North Korea from its terrorist blacklist this month to keep a nuclear disarmament pact from falling apart.

It would be an unprecedented test if North Korea fired all 10 of the surface-to-ship and ship-to-ship missiles, but intelligence sources quoted by the Chosun Ilbo paper said they thought the North may launch five to seven of them.

North Korea has forbidden ships to sail in an area in the Yellow Sea until October 15 in preparation for the launch, an intelligence source told the paper.

A South Korean defence ministry official declined to comment on the report but said the government had no indications of unusual activities in the North.

North Korea has a history of timing its missile launches during periods of increased tension or negotiation to signal a hard line, analysts say.

Diplomatic mission

US nuclear envoy Christopher Hill visited Pyongyang last week in a bid to convince North Korea to return to a disarmament-for-aid deal and halt plans to restart an ageing nuclear plant that makes bomb-grade plutonium.

Kyodo news agency, quoting unidentified Japanese sources, said Hill agreed that Washington would not make verification of Pyongyang's uranium enrichment programme or proliferation activities a condition of delisting.

In Vienna, diplomats said the International Atomic Energy Agency (IAEA) announced yesterday its monitors have been barred throughout the Soviet-era Yongbyon nuclear complex. Pyongyang ousted the monitors from the plutonium-producing area of the complex two weeks ago and vowed to start reactivating the facility within days.