U.S. President George W. Bush said Wednesday that his country would stop North Korea from transferring nuclear weapons and technology, warning Pyongyang it would then face "a grave consequence."

The Communist state staged an underground nuclear test on Oct. 9 and has described international attempts to prevent more testing as "an act of war." Officials in Washington are worried that the North Korean government might share information or nuclear material with Iran or al-Qaeda.

U.S. President George W. Bush warned North Korea that any attempt to sell or share nuclear material would be considered a grave threat to the United States.
(Ron Edmonds/Associated Press)

In an interview with ABC News, Bush said that any attempt to transfer nuclear material would be considered a grave threat to the United States.

"The leader of North Korea needs to understand that he'll be held to account," Bush said, "just as he's being held to account now for having run a test."

U.S. will defend Japan against North Korea: Rice

U.S. Secretary of State Condoleezza Rice met with political leaders in Japan on Wednesday, on the first stop on a round of diplomacy to rally support for enforcing UN sanctions against North Korea.
(Associated Press)

In Japan, U.S. Secretary of State Condoleezza Rice has also been warning Pyongyang about the consequences of its nuclear ambitions.

She told Japanese leaders on Wednesday that the United States is prepared to employ the "full range" of its military options to defend Japan if necessary, given that North Korea has tested a nuclear weapon.

"North Korea will be held accountable," Rice said in Tokyo.

Japan is the first stop on a round of diplomacy by Rice to rally support for enforcing United Nations sanctions against North Korea for its recent nuclear test. The sanctions were approved by the UN Security Council on Saturday.

Rice met Japanese Foreign Minister Taro Aso and is scheduled to meet Prime Minister Shinzo Abe on Thursday. She is also planning to visit South Korea, China and Russia.

"We have discussed the security situation in region in light of the North Korean nuclear test and earlier the North Korean missile test," she said.

"The United Nations Security Council has acted firmly and resolutely in both cases to say to the North Koreans that their behaviour is unacceptable and it is, in fact, isolating North Korea from the international community."

Rice said she and Aso have agreed to "work together and with other states" to implement sanctions swiftly and effectively against North Korea.

Japan won't join nuclear club: PM

Meanwhile, Abe said Japan has no plans to develop its own nuclear weapons despite the North Korean test.

Japan established a policy after the Second World War of not having, developing or allowing nuclear bombs on its soil, and Abe said there are no plans to deviate from that policy.

"In my opinion, that debate is finished," Abe told reporters.

Japan is expected to provide the support of its navy to the U.S. military when it conducts searches of North Korean vessels as part of sanctions imposed by the  Security Council.

Japanese aid to U.S. military a touchy issue

Providing logistical support to U.S. military vessels as they inspect cargo ships entering and leaving North Korea could be a sensitive issue in Japan, however,  because its constitution prohibits its armed forces from taking part in military operations abroad.

Japan has imposed sanctions of its own, banning North Korean ships from its ports, all North Korean imports and North Korean nationals from entering Japan. It has also suspended food aid to North Korea and imposed limited financial sanctions.

North Korea remains defiant, having rejected the UN sanctions, called them a declaration of war and threatened more nuclear tests.

Satellite data indicates increased activity around two North Korean sites that began a few days ago. At one site, the ground is being prepared and there is construction of some buildings.

With files from the Associated Press