Obama: North Korea 'Grave Threat'

South Korea's president is a hard liner, saying under no circumstances can North Korea be allowed to acquire nuclear weapons. CBS News National Security Correspondent David Martin reports that President Obama took just as hard a line today.

In the Rose Garden Tuesday, President Obama said "I don't think there's any question that would be a destabalizing situation that would be a profound threat to not only the United States security but to world security."

General James Cartwright, the American military's number two man, told a Senate committee that North Korea is still years away from being able to launch a missile that could hit the west coast of the United States.

"This is not scientific, but we're dealing in at least another 3 to 5 years minimum," Cartwright said during questioning by Sen. Evan Bayh, a Democrat.

The long range missiles North Korea has tested so far could reach Alaska and Hawaii.

In an exchange with Sen. Bayh, Cartwright said he would tell the President the chances of shooting them down are excellent.

"What are the percentages that we're going to be able to hit it and bring it down? What would you tell him," asked Bayh.

Cartwright responded, "90 percent plus."

The more immediate threat is that North Korea might sell nuclear or ballistic missile technology to a country like Iran or even a terrorist group like al Qaeda.

The U.N. Security Council passed sanctions giving the U.S. and other navies the authority to confront but not board any North Korean ship suspected of carrying arms. North Korea's response has been to continue preparations to launch more missiles.

To which President Obama said "belligerent, provocative behavior that threatens neighbors will be met with significant and serious enforcement of sanctions that are in place."