The blurry satellite images leave little room for doubt, say military officials: the Stalinist regime of North Korea — already a self-declared nuclear power — has fuelled and readied for test-firing an intercontinental ballistic missile capable of hitting the United States.

Japan, the US, Australia and New Zealand have spent the past few days seeking frantically to forestall a launch that could take place as early as tomorrow, threatening the despotic regime of Kim Jong Il with economic sanctions, immediate referral to the United Nations Security Council and other severe penalties.

Junichiro Koizumi, the Japanese Prime Minister, told reporters today: "I am still hoping that no missile will be launched ... but if one is fired, Japan will consult with the US and others and will have to take stern actions in response."

US State Department officials have reportedly resorted to the unusual step of telephoning North Korean diplomats at the UN to warn them directly of the consequences of proceeding.

A successful test-firing of the Taepodong-2 missile would have enormous implications for the security of the US, whose Western fringes could come within its range.

It would undo the hard-won and fragile makings of a diplomatic rapprochement with North Korea. It could even trigger a destabilising arms race in a region where brinkmanship is increasingly the rule, with Japan leading the way.

Even Beijing, which remains Pyongyang’s closest ally in the region, is reportedly infuriated with North Korea’s activities, and by the heightened risk that the six-party talks — the most promising chance of normalising regional relations with the hermit kingdom — will be derailed again.

Japanese government insiders told The Times last night that if Pyongyang proceeds with the test-firing Tokyo would significantly accelerate proposed legislation to overturn a 1969 parliamentary resolution and legitimise the use of space for military reconnaissance.

Japan has already begun a controversial joint missile defence programme with the US, and has emphasised that if any missile lands on Japanese territory, it will be considered an attack. Shinzo Abe, Japan’s chief Cabinet Secretary, pointedly referred yesterday to recent changes in the law that allow Japan to act on its own if threatened.

In 1998 North Korea caused a diplomatic furore by successfully firing a Taepodong-1 missile over Japan and into the Pacific, despite protests from the Clinton Administration. It has successfully launched several short-range missiles since 2000 but has stopped short of testing longer-range missiles since agreeing a moratorium in 1999.

According to Japanese reports, US satellite reconnaissance pictures indicate that North Korea has fuelled and prepared a newer version of the Taepodong missile with a range of between 3,500km and 6,000km.

Little is known about the missile or the payload it could carry. Nor, though North Korea claims to have developed nuclear weapons, is it clear whether the regime has the ability to build a nuclear warhead small enough to fit in a missile.

The Taepodong missiles are of predominantly North Korean construction, though their design and some of the parts are drawn from different sources including the former Soviet Union.

South Korean analysts who have in previous years played down the prospects of a launch are, on this occasion, far less certain that North Korea will back down in the face of international pressure.

Close observers of North Korean domestic politics say that one reason may be recent measures by Japan and the US to reduce the North’s sources of illegal income, such as Japanese gambling receipts and drugs.

With less hard currency to placate the military, Kim Jong Il may be under pressure to let the army fulfil its desire to test the most potent missile in the regime’s arsenal.

Times Recommends

• Times Charity Appeal: SolarAid
• Is it Black Monday all over again for Dubai?
• Behind the scenes at the biggest deal