The first ship, USS Freedom, suffered some technical glitches but also helped in distribution of relief supplies when Typhoon Haiyan struck the central Philippines last month.
"We believe that the U.S. presence in our region is a force for stability," Ng told a news conference, alongside Hagel.
Hagel reiterated the U.S. commitment to its rebalance toward Asia. He said he hoped a bipartisan budget compromise being put to Congress would provide more predictability for U.S. military planners over the next two years, and provide some reassurance to allies and friends "that we will stay committed to our allies and our interests around the world."
Hagel said he discussed with Ng China's new air defense identification zone which straddles some disputed islands further north and its "implications this has created for freedom of maritime and airspace navigation."
Hagel repeated the U.S. call for China not to implement it or take similar actions elsewhere.
China's new zone escalated its territorial dispute with U.S. ally Japan. There has been speculation that China could take similar steps to assert its claims in the South China Sea, where it has disputes with several Southeast Asian nations.
Ng did not directly address China's action, but emphasized the need for dialogue "to reduce the risk of miscalculation."
Also Thursday, Vice President Joe Biden spoke by phone with Japan's Prime Minister Shinzo Abe, and reiterated that China air defense zone would not affect U.S. operations in the East China Sea.
Biden also expressed support for steps to reduce regional tensions, the White House said.