Obama Wraps Up South Korea Visit, Says US Will Not Hesitate to Defend Ally

President Barack Obama has wrapped up a two-day visit to South Korea and is headed for the third stop in his four-nation tour, Malaysia -- the first visit by a sitting U.S. president since Lyndon Johnson traveled there in 1966.

Before his departure Saturday, Obama spoke to American troops stationed in Seoul, telling them that the United States "will not hesitate to use our military might to defend our allies and our way of life.'' The president's comment comes amid threats by North Korea to conduct its fourth nuclear test.

During a joint news conference with South Korean President Park Geun-hye in Seoul earlier Friday, Obama said Pyongyang will get nothing except further isolation if it proceeds with a nuclear test.

He added that America's commitment to South Korea will never waiver, and the U.S. and South Korea will stand "shoulder to shoulder" against North Korean provocation.

The South Korean leader said Obama's visit sends a firm message that North Korea's provocation will not be tolerated.

Obama also used the news conference to wade into a historical dispute that has strained relations between South Korea and Japan, which he also visited this week. He said Japan's war time use of so-called comfort women was shocking, but urged Seoul and Tokyo to look forward in their relationship.

The U.S. leader also expressed condolences to the families of the hundreds of children lost in last week's ferry accident.

Before Obama wrapped up a two-day visit to Japan earlier Friday, the two nations released a joint statement on security and trade. The countries said they share strong concern about China's air defense zone in the East China Sea, but reaffirmed interest in building productive ties with Beijing.

Following a Thursday meeting in Tokyo with Japanese Prime Minister Shinzo Abe, Obama explicitly stated the disputed Senkaku Islands fall under the treaty obliging the United States to defend Japan if attacked. Beijing also claims the islands, known as Diaoyu in China.

After Obama's Malaysia visit, his last stop will be the Philippines, which is also involved in a territorial standoff with China and has deepened its military cooperation with Washington as a result.

This is Obama's fifth visit to Asia since taking office in 2009. He has promised to make the Pacific region a greater economic, diplomatic and military priority for the United States.