North Korea is less able now to invade the South than it was a decade or more ago but has become a more lethal threat to Asia and the world, U.S. Defense Secretary Robert Gates said Friday in Tokyo.

"The character and priorities of the North Korean regime sadly have not changed," Gates said as he neared the close of a weeklong tour of Asian capitals worried that Pyongyang might start a new war on the Korean Peninsula.

"North Korea's ability to launch another conventional ground invasion is much degraded from even a decade ago, but in other respects it has grown more lethal and more destabilizing," Gates told students at Keio University.