The Pentagon on Wednesday confirmed the presence of five Chinese naval vessels in the Bering Sea between Russia and Alaska, which US President Barack Obama is currently visiting.

It was believed to be the first time Chinese military ships have been spotted in the area and is another sign of China's global presence expanding far beyond its own shores.

"We respect the freedom of all nations to operate military vessels in international waters in accordance with international law. We are aware of the five People's Liberation Army Navy (PLAN) ships in the Bering Sea," said Commander Bill Urban, a Pentagon spokesman, confirming a story first reported by the Wall Street Journal.

"This is the first time we have observed PLAN ships in the Bering Sea."

The vessels are in international waters near the Aleutians, a chain of islands that fan out from the Alaskan mainland. The boats comprise three combat ships, an amphibious ship and a replenishment vessel.

China became a permanent observer to the Arctic Council in 2013 and has shown increased interest in the region's energy reserves. The council's members are the eight Arctic states: Canada, Denmark, Finland, Iceland, Norway, Russia, Sweden and the United States.

Obama is currently in Alaska for a three-day tour of the vast state to raise awareness of the effects of climate change.

China on Thursday will assert its military might with a large parade commemorating the end of World War II. The display will feature 12,000 Chinese troops marching through Tiananmen Square alongside gleaming tanks and missiles, as fighter jets scream overhead.