The White House said on Monday that North Korea may be affected by a US-led, 11-country effort to develop skills for sea, air and ground interdiction of weapons-of-mass-destruction transfers.
The first such exercises, involving planning for high seas interdictions, will take place next month off the coast of Australia shortly after North Korean disarmament talks are held in China.
US Department of State spokesman Richard Boucher told reporters on Monday that the exercises are not aimed solely at North Korea.
"It's a global initiative with global reach and it's aimed at stopping the flow of weapons of mass destruction, missiles and related materials," Boucher said.
But he noted that North Korea has a long history of involvement in proliferation activities.
"If North Korea wants to continue to aggressively proliferate missiles and related technologies, it might find itself affected by this initiative," he said.
US officials have said previously that North Korea has sold missiles to Syria and Iran and has engaged in a determined marketing campaign in other countries.
The US President George W. Bush administration is hoping to curb these exports as well as North Korean imports of materials needed for nuclear-weapons programs.
Boucher described North Korea and Iran as "two of the greatest proliferators in the world -- potential proliferators."
Joining with the US in the September exercises will be Australia, France, Germany, Italy, Japan, the Netherlands, Poland, Portugal, Spain and Britain.
At the Aug. 27 to 29 talks in China, the US will demand that North Korea shut down its nuclear-weapons programs verifiably and permanently. North Korea is expected to be seeking security guarantees and economic benefits in return.
In addition to the US and North Korea, other participants at the Beijing talks will be South Korea, Japan, China and Russia.
Meeting with China's leaders Monday in Beijing, Australian Prime Minister John Howard said, "The North Korean nuclear threat is about as real and serious a threat as we can have anywhere in either the region or the world."
Bush said convincing North Korea's Kim Jong Il to give up his nuclear-weapons program will be difficult -- but not impossible.
"I'd like to solve this diplomatically and I believe we can," he told Armed Forces Radio and Television Service. "It's going to take a lot of persuasion by countries besides the US to convince him."
Meanwhile, North Korea warned on Monday that Japan could spoil the Beijing talks with its insistence on raising the issue of Japanese citizens abducted to the North years ago.
North Korea touched off a political firestorm in Japan last September when it acknowledged that its agents abducted or lured 13 Japanese nationals in the 1970s. It said eight had died.
Boucher seemed to have no objection to any such Japanese effort to raise the issues in Beijing, suggesting that the talks won't necessarily be limited to North Korea's nuclear-weapons program.