TOKYO, Jan. 8 (UPI) -- North Korea is a top concern for the United States Navy.
North Korea's recent claim of a successful hydrogen bomb test, however, has Aucoin deeply concerned.
"What keeps me up is the Korean peninsula. Day to day we watch North Korea very closely. What happened there definitely got our attention," Aucoin said during an interview aboard the aircraft carrier USS Ronald Reagan.
The Seventh Fleet commander also urged North Korea to abandon its nuclear weapons during his first meeting with reporters since assuming his position in September.
"We want them to abandon any nuclear activities and comply with the international commitments and obligations. Until they do that, they're not going to achieve prosperity," Aucoin said.
Stars and Stripes reported another source of U.S. uneasiness in the maritime region is unabated Chinese activities in the South China Sea.
Aucoin said Friday that China should be more transparent about its activities in the disputed Spratly Islands.
Earlier on Thursday, Pentagon officials expressed concern after China landed three commercial planes on a new runway on reclaimed land built over Fiery Cross Reef.
"We would like China to help with the security and stability of the region by being clear with what they're doing," Aucoin said. "U.S. Navy ships sail where we want to in international waters. But merchant vessels are already feeling this. They need to operate in these international waters, so it would be very helpful for China to abide to these international standards and norms."
U.S. officials are not alone in their opposition to China's unilateral activities.
On Friday, Vietnam filed its second official protest with China. Hanoi said Beijing violates Vietnam's sovereignty and threatens peace and stability in the region.