Countries taking part in negotiations to end North Korea's nuclear programs are seeking diplomatic means to defuse tensions over the North's missile launches. North Korea defied international condemnation of the launches, vowing to retaliate should it be pressured from firing more missiles.

Washington and Tokyo continued their strong condemnation of Pyongyang over the missile launches, and Beijing reiterated the importance of diplomacy.

The Chinese Foreign Ministry said it is sending its own top negotiator, Vice Foreign Minister Wu Dawei, to Pyongyang next week. He will make another push to get the North Koreans to return to stalled six-party negotiations over Pyongyang's nuclear weapons programs, a forum the Chinese believe can be used to discuss a variety of issues.

Chinese Foreign Ministry spokeswoman Jiang Yu says China will continue efforts to promote the six-party talks, and strive for the peace and stability of the Korean peninsula.

Shinzo Abe, Japan's chief Cabinet secretary, called for North Korea to stop its missile tests immediately, and to return to the six-party talks with no conditions. Japanese Prime Minister Junichiro Koizumi questioned why North Korea was launching the missiles, saying it had nothing to gain from such an act.

The Japanese Foreign Ministry says Mr. Koizumi and President Bush have agreed to cooperate in crafting a strong message to North Korea from the United Nations Security Council.

South Korean President Roh Moo-hyun spoke by telephone with President Bush. Mr. Roh, whose government is at odds with the United States over Seoul's policy of engagement with the North, also promised to cooperate on diplomatic steps to address the issue.

The chief U.S. envoy to the six-party talks, Christopher Hill, arrives Friday in Asia to consult with China, South Korea, and Japan.

Pyongyang has refused to return to those negotiations since November, despite agreeing in principle in September to dismantle its nuclear programs in exchange for economic and diplomatic incentives.

North Korea defended its missile launches as a "sovereign right," and warned it would fire more missiles to bolster its "self-defense."

A statement read on state-owned television says North Korea will take "stronger action" should other countries "pressure" it to stop further launches.

North Korea fired seven missiles Wednesday, including its long-range Taepodong-2, which is potentially capable of reaching the United States.

Washington denounced the launches as a provocation.

The launches were the first time North Korea tested a long-range missile in eight years - breaking a moratorium it agreed to in 1998.