SEOUL, South Korea - Japan and Washington agreed Friday to strengthen cooperation on missile defense amid concerns of a possible long-range rocket launch by North Korea, as U.S. forces wrapped up massive Pacific war games in a show of military might.
The five days of exercises - the largest in the Pacific since the Vietnam War - brought together three aircraft carriers along with 22,000 troops and 280 warplanes off Guam in the western Pacific.
The exercise "was a demonstration of the U.S. Pacific Command's ability to quickly amass a force ... and project peace, power and presence in the region," Air Force Lt. Gen. David Deptula told The Associated Press.
In Tokyo, Japanese Foreign Minister Taro Aso and U.S. Ambassador Thomas Schieffer signed documents about cooperation on joint ballistic missile defense development, the Foreign Ministry said in a statement. Japan's Defense Agency also said a high-resolution radar that can detect a ballistic missile has been deployed at a base in northern Japan.
North Korea has made recent moves that would enable it to launch a long-range missile, U.S. and Asian officials have said. Intelligence reports say fuel tanks have been seen around a missile at the North's launch site on its northeastern coast, but officials say it's difficult to determine by satellite photos if the rocket is actually being fueled.
The North has said it is willing to talk to Washington about its missile concerns, repeating its long-held desire for direct meetings with the Americans. Washington, however, has refused, and insists it will only meet the North in six-nation talks aimed at ridding Pyongyang of its nuclear weapons program.
South Korean Unification Minister Lee Jong-seok said Friday that "it seems clear that even if North Korea fires a missile, the United States would not make a compromise."
Lee said a "series of activities by North Korea" were consistent with a missile launch, and he pressed the North to return to the multinational talks.
"North Korea should immediately halt moves of its missile launch," Lee said.
South Korean Foreign Minister Ban Ki-moon is seeking to visit China next week to discuss the missile issue, but plans aren't yet confirmed, his ministry said.
U.S. officials have warned North Korea that a missile launch could have serious repercussions.
"We still hope that they recognize that launching that missile would only isolate them further, and that they will make the right decision and not launch the missile," U.S. Ambassador to South Korea Alexander Vershbow told The Associated Press on Friday in Seoul. He spoke after a ceremony marking the anniversary of the 1950 start of the Korean War, which ended in a 1953 cease-fire that has yet to be replaced by a peace treaty.
The missile concerns have prompted China and Russia - Pyongyang's last two major allies - also to warn the North against a launch.
Moscow summoned the North Korean ambassador to the Foreign Ministry on Thursday to express its concern. China also urged the North on Thursday to return to the international nuclear talks, which Pyongyang has boycotted since November in anger at U.S. restrictions on its financial dealings.
On Thursday, the White House said it was committed to seeking a diplomatic solution and rebuked an opinion piece in The Washington Post by former U.S. Defense Secretary William Perry that suggested the United States launch a pre-emptive strike against a North Korean missile.
"We think diplomacy is the right answer and that is what we are pursuing," U.S. National Security Adviser Stephen Hadley told reporters. "The way out of this is for North Korea to decide not to test this missile."
The U.S. military on Thursday said it had successfully tested a missile defense system against a medium-range missile in a previously scheduled exercise.
Hadley said the U.S. missile defense system had "limited operational capability" to protect against weapons such as the long-range missile the North is possibly moving to launch.
South Korea said Friday it was pushing for a summit in September between President Roh Moo-hyun and President Bush.
The mention of a summit by Roh's office before plans were complete is contrary to usual diplomatic protocol, and appeared aimed at contradicting perceptions of a fray in the two countries' alliance over differences in dealing with North Korea. The Bush administration has sought to pressure the North, while Seoul has taken the path of reconciliation.
The White House has spoken by phone with more than a dozen world leaders about the missile issue - but hasn't talked directly with Roh since he met Bush in South Korea on the sidelines of an Asia-Pacific summit in November.
In other moves for dialogue, Indonesian President Susilo Bambang Yudhoyono will travel to both Koreas in July, his Foreign Ministry said.