SEOUL, South Korea — Taunting the United States on its birthday by firing seven missiles was a provocative move that some experts said might have been intended to discourage deployment of new missile defenses against the communist state.

The Independence Day launch was the North's biggest one-day barrage of test missiles in three years. It drew strong criticism from countries in the region, as well as renewed resolve from the Obama administration to punish Pyongyang for its continued defiance of U.N. resolutions.

Pyongyang made no comment yesterday about the missiles. But launches had been expected this weekend because North Korea had warned ships to avoid waters near its east coast through July 10.

South Korea and Japan both condemned the launches, with Tokyo calling them a "serious act of provocation." Britain, France and Australia issued similar statements.

Australian Foreign Minister Stephen Smith said North Korea's capabilities were getting better.

"If you look at their most recent efforts, the most worrying thing is not their current capacity in terms of distance or scope but how they have improved," he told the Nine Network today.

"We have seen improvements regrettably in their technology and their approach," he said, emphasizing the latest missile tests were clearly a provocative act aimed at the U.S.

Russia and China, both close to North Korea, expressed concern over an "escalation of tension in the region," the Russian Foreign Ministry said in a statement after a meeting in Moscow.

In Washington, the Obama administration reacted with dismay to the latest in a series of North Korean provocations that included an underground nuclear test on Memorial Day.

"This type of North Korean behavior is not helpful," said State Department spokesman Karl Duckworth. "What North Korea needs to do is fulfill its international obligations and commitments."

South Korea's Yonhap news agency suggested launch activity may be winding down, at least for now. It reported yesterday, citing an unidentified military official, that the North was pulling personnel from its missile launch site and allowing ships to sail off the coast.

South Korea's Defense Ministry said it could not confirm the report.

Last month, concerns of a possible long-range ballistic missile launch by North Korea over the Pacific Ocean prompted the U.S. to position a missile defense system around Hawai'i, which is more than 4,500 miles from North Korea.

U.S. analysts said yesterday there are no indications a launch of a Taepodong-2 missile in the direction of Hawai'i is imminent. Alaska and Guam also would be within striking distance of a Taepodong-2.

An advanced Taepodong-2, which reportedly is under development, would have a potential range of about 5,000 miles, putting the U.S. west coast, Australia and eastern Europe also within striking distance.

POSSIBLE WARNING

Two senior officials in Obama's administration said any reaction to yesterday's launch was likely to be muted to avoid giving attention to Pyongyang or antagonize it. They spoke on condition of anonymity because they were not authorized to discuss the matter publicly.

Yesterday's display was similar to one three years ago, also while the U.S. celebrated the Fourth of July during another period of tensions over Pyongyang's nuclear weapons program.

The number of missiles — seven — was the same, though in 2006 North Korea also launched a long-range rocket that broke apart and fell into the ocean less than a minute after liftoff.

South Korea said the rockets, all appearing to be short-range ballistic missiles, splashed harmlessly into the Sea of Japan (East Sea).

Some independent experts said the firing of multiple missiles may have been intended as a warning to adversaries that North Korea would seek to overwhelm their missile shields.

"The chief challenge with missile defense is coping with large numbers of missiles, and the firing of seven has a saturation quality to it," said Dennis M. Gormley, a former member of numerous military and intelligence advisory boards and a senior fellow at the Monterey Institute's James Martin Center for Nonproliferation Studies in Washington. "It at least raises the specter of these kinds of attacks."

FURTHER ISOLATION

A senior administration official predicted the tests will lead to the further isolation of North Korea, which was hit with new U.N. Security Council sanctions last month after its May 25 nuclear test.

The sanctions have infuriated the government of Kim Jong Il, which responded to them by vowing last month never to give up nuclear weapons and to start making more with enriched uranium.

When challenged, North Korea has a history of rattling its military hardware. It fired four short-range missiles into the sea off its east coast on Thursday, when senior U.S. diplomats were in Beijing trying to persuade the Chinese to be more diligent in enforcing sanctions against the North.

After North Korea's warning to local shipping traffic, there had been speculation that it might attempt a longer-range missile test.

Such an act would have been far more provocative, said David Albright, a former U.N. weapons inspector and president of the Institute for Science and International Security in Washington. "In that sense, at least, today's launch could have been far worse," he said.

The South Korean military said it is "fully ready to counter any North Korean threats and provocations based on strong South Korea-U.S. combined defense posture." The U.S. military has about 28,500 troops in South Korea.

The Washington Post, Associated Press and Bloomberg News Service contributed to this report.