“Obviously, it is a bit of an effort to get attention, perhaps because so much attention has been focused on the Iranians,” Hadley told reporters.
But like many U.S. officials, he said it was impossible to be sure about the secretive communist state’s motives.
“It’s very difficult to know what the North Koreans think they are doing this for,” Hadley said.
Iran has been the main focus of U.S. nuclear diplomacy in recent months.
Washington has pressed a recalcitrant Tehran to suspend uranium enrichment that the United States says is to develop nuclear weapons but the Iranians say is for civilian power.
The United States and five other world powers have demanded Tehran respond this week to an offer of incentives to curb its nuclear fuel program.
But Hadley, President George W. Bush’s chief adviser on national security, said the United States hoped Iran and North Korean would draw the same lesson.
“In both cases, Iran and North Korea, even though the constellation of players may be a little different, the international solidarity is the same and the message that we do not want a nuclear North Korea or a nuclear weapon-armed Iran, that message is the same message,” he said.
Asked whether the North Koreans were trying to send Washington a message to mark America’s Independence Day, White House spokesman Tony Snow said: “I’d rather not try to read the mind of a leader … in a non-transparent society.”
He insisted that whatever the motivation, “North Korea has isolated themselves.”
