North Korea is demanding that Tokyo immediately lift sanctions imposed on Pyongyang in response to its test launch of missiles.
A North Korean envoy to Japan (Song Il Ho) says his country will retaliate with stronger measures if the sanctions are not lifted.
After North Korea's test-fired seven missiles on Wednesday, Tokyo barred a North Korean ferry from Japanese ports for six months and banned North Korean officials from entering the country.
South Korea today rejected Pyongyang's request for military talks, saying they were inappropriate at this time. But it said ministerial talks will go ahead as scheduled next week.
U.S. Assistant Secretary of State Christopher Hill is in Asia to discuss a unified strategy in confronting North Korea. He met with officials in Beijing and will travel later in the day to Seoul. Hill is also to go to Japan.
The U.N. Security Council is considering a proposal by Japan that would prevent the transfer of funds, technology and goods that would benefit North Korea's missile and nuclear programs.
The measure has broad backing in the 15-member Security Council. However, Russia and China want a weaker resolution that does not include sanctions.
President Bush held talks (over the phone) late Thursday with Australian Prime Minister John Howard, who expressed support for efforts to ensure that North Korea ends it missile and nuclear programs.
During an interview with CNN, Mr. Bush said the launches by North Korea provide an opportunity for the world to come together to deal with Pyongyang's nuclear ambitions.
North Korea says the tests were successful and that it will carry out more launches.
But, Washington says none of the seven missiles posed any threat to the United States. It says the one long-range missile failed less than a minute after launch.