The U.S. suggested Thursday it has limited ability to shoot a North Korean missile out of the sky and spurned suggestions of a pre-emptive strike on the ground. Still, it warned the Koreans would pay a cost for a missile launch.

The solution, said President Bush's national security adviser, is for the North to "give it up and not launch" the long-range missile that the U.S. believes is being fueled and prepared.

"We think diplomacy is the right answer and that is what we are pursuing," Stephen Hadley told reporters.

The words came as tensions persisted over North Korea's apparent preparations to test-fire a Taepodong-2 missile — and amid disagreements over U.S. military options for responding. The missile, with a believed range of up to 9,300 miles, is potentially capable of reaching the mainland United States.

A Pentagon official said Pyongyang risked unspecified retaliation in proceeding.

"If such a launch takes place, we would seek to impose some cost on North Korea," Peter Rodman, assistant secretary of defense for international security affairs, told the House Armed Services Committee.

Vice President Dick Cheney brushed aside a suggestion by former Defense Secretary William Perry that the Korean missile be obliterated at the launch site.

"I appreciate Bill's advice," Cheney said in an interview with a cable network. "I think, obviously, if you're going to launch strikes at another nation, you'd better be prepared to not just fire one shot. And the fact of the matter is I think the issue is being addressed appropriately."

Cheney said that North Korea's "missile capabilities are fairly rudimentary" and that "their test flights in the past haven't been notably successful. But we are watching it with interest and following it very closely."

Missile defense experts disagreed on current U.S. ability to destroy such a missile once it is fired. But they seemed in agreement that shooting at it — and missing — would be a huge embarrassment.

"Either it won't work, in which case you've just undermined the rationale for the system. Or if it does work, you have created an even bigger international crisis," said Ivo Daalder, a White House national security aide in the Clinton administration.

"Even when you do intercept it, there's the real question of what have you done? These are international waters. Is this an act of war?" said Daalder, now a foreign policy and missile-defense specialist at the Brookings Institution.

Loren Thompson, a defense consultant at the Lexington Institute in Arlington, Va., said there are "two basic problems" with trying to shoot down a Korean missile.

"Our system is barely operational. And the impact on Korean perceptions if we miss could be counterproductive," Thompson said.

"Bombs work a lot better than missile defense systems," Thompson added, echoing Perry's suggestion for a pre-emptive air strike.

In an opinion article in Thursday's Washington Post, Perry and former assistant defense secretary Ashton B. Carter wrote that Bush should immediately declare that the U.S. would destroy the missile before it could be fired.

"Diplomacy has failed, and we cannot sit by and let this deadly threat mature," wrote Perry and Carter. Both served in the Clinton administration.

Hadley, the president's national security adviser, brushed aside such suggestions.

When asked if the U.S. would consider launching such a strike on the launch site on Korea's northeastern coast, Hadley responded: "We hope it (North Korea) would come back to the table, and we hope it would be a little sobered by the unanimous message that the international community has sent."

International talks to persuade North Korea to restrict its nuclear program have not been held since last November. The five other nations party to the talks — the United States, China, Russia, Japan and South Korea — have all strongly urged the North not to launch the missile.

Click here to read about international pressure put on North Korea to stop missile launch.

Hadley, who briefed reporters in Budapest, Hungary, during a Bush visit, expressed some reservations about the ability of the United States to intercept and destroy such a missile, noting that the U.S. missile defense system was still in an early stage.

"It is a research development and testing capability that has some limited operational capability," Hadley said.

The missile defense system, which now includes advanced radar and interceptor missiles based in Alaska and California, has suffered repeated test failures since Bush ordered the program accelerated in early 2001.

Under the program, interceptor missiles are designed to strike and destroy incoming ballistic missiles.

The Pentagon has developed a rudimentary system that it says is capable of defending against a limited number of missiles in an emergency — with a North Korean attack particularly in mind.

Some $91 billion has been spent over the past two decades on the program first proposed by President Reagan, according to congressional auditors.

"If the North Koreans fire the missile and the president chooses to launch an interceptor, the administration has an odd set of options," said Daryl Kimball, executive director of the private Arms Control Association.

"If it hits the missile, will the North Koreans consider that an act of war? And if the interceptor misses the North Korean test missile, it would simply illustrate the fact that we spent tens of billions of dollars for a system that's not effective — even against one missile from one known launch point."