The commander of United States Forces in South Korea says he believes North Korea is likely to conduct further nuclear weapons tests, but that the alliance between Washington and Seoul will remain strong enough to deter any North Korean aggression.

U.S. General Burwell Bell said Monday in Seoul, that North Korea's nuclear weapons test on October 9 probably will not be the last.

"I can only surmise that since they've tested one, that we would see some time in the future yet again another test of a nuclear device," he said. "I hope that that is not the case."

Bell commands about 28,000 U.S. military personnel who are in South Korea under a mutual defense treaty enacted after the 1950-1953 Korean War. Bell briefed reporters Monday on recent high-level talks between South Korea and the United States.

North Korea says it needs a nuclear arsenal to deter U.S. aggression. Washington has said it has no intention of attacking the North. Bell said Monday the alliance's "business" is to deter North Korea - and if deterrence fails, to defeat it - but not to launch a first strike.

"The notion of Combined Forces Command developing pre-emptive strike plans - as has been reported in some news media - is simply not the case," he said.

Under the present terms of the U.S. - South Korea alliance, U.S. officers would command South Korean forces in the event of war. General Bell says this month's high-level talks in Washington arrived at a timetable for returning wartime command to South Korea sometime between 2009 and 2012, with details to be negotiated.

The administration of South Korean President Roh Moo-hyun has made the return of wartime operational control a priority as part of its policy of seeking greater strategic autonomy from the United States.

Bell says the U.S. role in defending South Korea will become, in his words, "more air- and naval-centric" as time goes on, shifting more responsibility to South Korea's approximately half a million strong forces.

Bell called on North Korea to stop testing and building nuclear weapons, and to return to six-nation talks aimed at ending its nuclear programs. The United States, South Korea, Japan, Russia, and China say the North can receive economic and diplomatic benefits if it abandons its nuclear weapons program.