U.S. Defense Secretary Leon Panetta left for Asia, where he aims to strengthen ties with allies of the United States.

Panetta's first stop is Indonesia, followed by Japan and South Korea, where bases form the core of the U.S. military presence in Southeast Asia.

The defense secretary will meet with leaders and government officials. Several countries in the region have concerns about China's expanding military and are engaged in disputes with Beijing.

Panetta's trip, his first to Asia as defense secretary, coincides with a second round of rare direct talks between U.S. and North Korea on Pyongyang's nuclear program. U.S. and North Korean officials plan to meet Monday and Tuesday in Geneva.

The meeting could determine if conditions are ready for a resumption of six-nation talks on North Korea's nuclear disarmament. Pyongyang abandoned those talks in 2009.

The United States and South Korea say they want evidence that Pyongyang is serious about returning to the negotiating table.

The U.S., Russia, China, Japan and the two Koreas are parties to the six-nation disarmament talks.