Japanese Prime Minister Shinzo Abe agreed with US President George Bush today to take strong steps against North Korea at the UN Security Council over its nuclear weapons test.
The two leaders, who spoke by phone, called the test a grave threat to international security and agreed to push for ``decisive action'' at the Security Council, Japan's Foreign Ministry said.
They also affirmed the strength of the US-Japan alliance, it said in a statement. Abe took the call in Seoul, where he held talks with South Korean President Roh Moo-hyun.
Tokyo dispatched three T-4 supersonic aircraft to waters between Japan and the Korean Peninsula to monitor radiation levels. The aircraft will collect air samples at an altitude of about 9,900ft which will be analysed for radioactivity, according to the Defence Agency. More flights were scheduled later in the week.
On his return to Tokyo, Abe instructed Chief Cabinet Secretary Yasuhisa Shiozaki to co-ordinate Japan's response with that of other countries.
``He told me to be prepared (because the test could) greatly affect Japan,'' Shiozaki said after meeting Abe later.
Earlier, Shiozaki told reporters the test was a serious challenge to Japan's national security and that Tokyo would respond with immediate and stern measures. He did not say what the measures might be.