"It is good to spell out an idea which can move things in a positive manner," Chief Cabinet Secretary Yasuo Fukuda told reporters.

But he added: "We need to ascertain whether they will freeze everything and what they will actually do."

The offer was announced Tuesday by Pyongyang's official Korean Central News Agency, which also called for "simultaneous" US actions, including removing North Korea from a State Department list of countries accused of sponsoring terrorism, lifting sanctions and resuming energy aid.

In Washington, US Secretary of State Colin Powell said Tuesday he was encouraged by the North Korean offer which he called as an "interesting step on their part, a positive step."

The offer came as two unofficial US delegations arrived in Pyongyang, hoping for a tour of the Yongbyon nuclear complex at the center of a crisis which erupted in October 2002, when Washington accused North Korea of breaching an anti-nuclear pact.

Fukuda also conditionally welcomed a commentary made Tuesday in North Korea's official newspaper Rodong Sinmun that proposed an improvement in bilateral relations.

"We will welcome it if they are willing to hold talks in a friendly manner and in good faith," Fukuda said.

North Korean leader Kim Jong-Il and Japanese Prime Minister Junichiro Koizumi agreed in a historic summit in 2002 to work for normalisation of relations between their countries.

But the process of rapprochement has been stalled by public anger here over Kim's admission that North Korean agents kidnapped Japanese citizens during Cold War years.

WAR.WIRE