Chinese frigate Yueyang, July 25, 2014 (photo: Specialist 1st Class Shannon Renfroe/US Navy)

Five Chinese navy ships are currently operating in the Bering Sea, off the coast of Alaska, the first time the U.S. military has seen such activity in the area, Pentagon officials said Wednesday.

The officials said they have been aware in recent days that three Chinese combat ships, a replenishment vessel and an amphibious ship were in the vicinity after observing them moving toward the Aleutian Islands, which are split between U.S. and Russian control.

They said the Chinese ships were still in the area, but declined to specify when the vessels were first spotted or how far they were from the coast of Alaska, where President Barack Obama is winding up a three-day visit….

The presence of the Chinese ships so close to U.S. shores is the latest demonstration of how China’s military is rapidly expanding its operations far from its own coast to protect the nation’s growing global interests….

The Pentagon official said there were a “variety of opinions” on how to interpret the Chinese ships’ deployment.

“It’s difficult to tell exactly, but it indicates some interest in the Arctic region,” the official said. “It’s different….”

China’s navy confined itself to patrolling the nation’s coast for the first five decades after the Communist takeover in 1949. But in the past few years, it has ventured deep in the Pacific and Indian Oceans and even the Mediterranean Sea.

The Chinese navy has taken part in antipiracy patrols in the Gulf of Aden since 2008 and held joint naval drills with Russia in the Mediterranean in May. Last year, Chinese navy ships made their debut at U.S.-led Rim of the Pacific, or Rimpac, joint naval drills in Hawaii.