|PIC1|The United States has also said that it will seek UN sanctions to curb North Korea's import and export of material that could be used to make and deliver weapons of mass destruction, as well as its illicit financial activities.
In addition, a document later presented to the press confirmed that the US had proposed a trade ban on all military and luxury items travelling into the country, as well as the power to inspect all cargo entering or leaving the country, and to freeze assets connected to North Korea's weapons programs.
Joining the US in the strict stance were Britain and France, who stated that they would jointly seek a resolution under Chapter 7 of the UN Charter to request sanctions.
British Prime Minister Tony Blair also today condemned North Korea's test as a "completely irresponsible act".
Blair said the test, reportedly held at 2.36am British time, showed the country's "disregard" for the concerns of the international community.
He said: "I condemn this completely irresponsible act by the government of the DPRK (Democratic Peoples' Republic of Korea).
"The international community has repeatedly urged them to refrain from both missile testing and nuclear testing.
"This further act of defiance shows North Korea's disregard for the concerns of its neighbours and the wider international community."
Mr Blair added that the test "contravened" North Korea's commitments under the Nuclear Non-Proliferation Treaty and UN Security Council Resolution 1695.
The Foreign and Commonwealth Office (FCO) said the international community would react "robustly" to the test, claimed by North Korea to have been held at an underground site in the north-east of the country.
An FCO spokesman said: "This nuclear test is viewed by the UK, and will be viewed by the rest of the international community, as a highly provocative act to which we will respond robustly.
"It will raise tensions in an already tense region and have repercussions internationally."
Throwing its weight into the dispute, the US expressed to the UN Security Council that it would view any attack from North Korea towards Japan on South Korea as a direct attack on the United States.
Thousands of US troops are already stationed in Japan and South Korea as part of the US's defence agreements with the countries.
However, North Korea's ambassador to the UN was defiant, stating that the Security Council should congratulate his nation for its successful nuclear test, rather than passing "useless" resolutions or statements.
The ambassador stated that he was proud of the North Koreans who conducted the test and said it will contribute "to the maintenance and guarantee of peace and security in the peninsula and the region".
The British UN Ambassador, Emyr Jones-Parry said, "We've already said that were there to be a nuclear test it would be a threat to international peace and security. I think it follows that action under Chapter 7 is what is appropriate. We'll have to look at what sort of measures can be agreed by the council but certainly the United Kingdom would support proposals put down to that effect."
Following the reports early on Monday that the nuclear tests had been carried out, The UN added North Korea to the agenda of an already scheduled council meeting that officially nominated South Korean Foreign Minister Ban Ki-moon as the next secretary-general. The South Korean said he would immediately work to resolve the North Korean crisis.
If appointed to the top job, Ban said he would "contribute as much as I can to the resolution of all kinds of problems including the North Korean nuclear issue that may threaten international peace and security."
The timing of North Korea's test has increased speculation that North Korea wanted to express its opposition to Ban's selection as the Security Council's candidate to succeed Kofi Annan.
The opposition has arose following Ban previously saying that one of his first acts would be to go to North Korea.
The 15-member Security Council's recommendation for the next secretary-general will be given to the 192-member General Assembly, which must give final approval. Ban will be the only name on the ballot.
Ban, 62, topped four informal polls in the council, and in the final one he was the only candidate not to get a veto by one of its five permanent members. With that strong indication of the vote given, the other five candidates stepped down from the election process.