North Korea has begun fuelling a rocket for a launch that the West considers a missile test, a Japanese newspaper reported Thursday, citing a source "close to the government" in Pyongyang.

"The launch is coming closer. The possibility is high that the launch date will be set for April 12 or 13," the source said according to the Tokyo Shimbun in a report from Seoul.

It cited the source as saying that North Korea had begun injecting liquid fuel into the rocket.

The paper also said a diplomatic source had confirmed that North Korea has moved the rocket to a launch pad in Tongchang-ri in the country's far northwest.

The report came after North Korea insisted Tuesday it would go ahead with what it says is a satellite launch, snubbing a call from US President Barack Obama to drop the plan and accusing him of a "confrontational mindset".

The United States has suspended plans to send food aid to North Korea, saying it has broken a promise to halt missile launches and cannot be trusted to give the help to those who need it, a Pentagon official said Wednesday.

The West and North Korea's Asian neighbours have urged Pyongyang to give up on the rocket launch, which is seen as the pretext for testing ballistic missile technology. (AFP)