Malaysia's defense minister is voicing fears that tensions in the South China Sea could "spiral," as he and his regional counterparts meet to discuss freedom of navigation and ways to avoid incidents, with American, Chinese and Japanese officials present as observers, Nikkei Asian Review reported. In Seoul, South Korea said the sea lanes must stay open.

On the sidelines of the meetings on Tuesday and Wednesday outside Kuala Lumpur, Malaysian Defense Minister Hishammuddin Hussein will have an official visit from Chinese counterpart Chang Wanquan before flying with U.S. Defense Secretary Ashton Carter to a U.S. aircraft carrier on an Osprey aircraft, Nikkei said.

"What we are concerned about are unintentional accidents in the sea that, if not managed, would spiral to something bigger," Nikkei reported Hussein as saying Monday, before the two-day meeting. "If small countries like Malaysia are not united within the 10 ASEAN countries, we will be at the mercy of the superpowers." ASEAN is the Association of Southeast Asian Nations.

Tensions have heightened since China asserted its claims over most of the South China Sea, including stepping up island-building "reclamation" activities and constructing airstrips and other facilities in disputed areas in the past year. Last week, the U.S. challenged China by sailing a warship close to one of those areas, drawing a protest from Beijing. Also last week, an international arbitration court said it had jurisdiction to rule over a dispute between China and the Philippines, which China rejects.

In a Monday news conference with Carter in Seoul, South Korean Defense Minister Han Min-koo said his country was for keeping the South China Sea open. 

“It is our stance that freedom of navigation and freedom of flight should be ensured in this area, and that any conflicts be resolved according to relevant agreements and established international norms,” the Wall Street Journal reported Han as saying.