WASHINGTON (AP) — The top U.S. military commander in Korea said Tuesday that U.S. and South Korean forces are prepared for "anything North Korea can throw at us," regardless of the state of leader Kim Jong Il's health or of internal North Korean politics.

General Walter "Skip" Sharp told reporters that Kim should stop threatening the world with nuclear and missile tests and instead take care of his people and follow through on past commitments to abandon nuclear weapons programs.

The United States and North Korea's neighbors are working to enforce sanctions imposed by the United Nations to punish North Korea for its nuclear test in May, even as they push the North to resume stalled six-nation nuclear disarmament talks.

Sharp, who spoke by video conference from New York, said that if diplomatic efforts fail, he is "absolutely confident" that the United States and South Korea can intercept North Korean missiles fired at the South and quickly and successfully defeat any land or sea attacks.

The North has threatened a "thousand-fold" military retaliation against the U.S. and its allies if provoked and has boasted of a "strong army that can impose merciless punishment against those who offend us." North Korea devotes much of the country's scarce resources to its 1.2 million-member military.

North and South Korea face off across the world's most heavily fortified border, the so-called Demilitarized Zone that has separated the two neighbors since the Korea War ended in 1953. The United States, South Korea's top ally, has 28,500 troops stationed in the country as a deterrent. South Korea has about 650,000 troops.

Kim appeared frail and gaunt in a public appearance last week, fueling speculation that his health is failing. Neighboring governments are worried that a dangerous political power struggle in the North could ensue if Kim were to die before any successor could solidify his rule.

Sharp would not comment on reports that Kim has cancer and has named his youngest son as heir. Sharp urged whoever leads North Korea to cease threats and said the United States was prepared for any North Korean aggression.

Sharp was also asked about North Korea's suspected involvement in cyberattacks last week that caused Web outages in the United States and South Korea. Sharp would not confirm news reports that the North was involved, saying officials still were working to see where the attacks came from. The U.S. military, he said, has not been hurt by the attacks, although he called them a worry.

The attacks, in which floods of computers tried to connect to a single Web site at the same time to overwhelm the server, caused outages on prominent government-run sites in the United States and South Korea.

North Korea quit the six-nation nuclear negotiations in April in anger over a U.N. rebuke of its long-range rocket launch. The country has since further ratcheted up tensions, conducting its second nuclear test and a series of banned missile launches.