The Pentagon said it was the first time the U.S. had seen Chinese ships in the Bering Sea, but the vessels were sailing in global waters.

Two US defense officials, speaking to Agence France-Presse on condition of anonymity, said the USA had identified three combat vessels, a replenishment vessel and an amphibious landing vessel from China’s People Liberation Army Navy (PLAN).

The sight of the ships comes just as President Obama ends his three-day visit to Alaska to raise awareness about climate change.

“This is the first time we have observed [Chinese navy] ships in the Bering Sea”, said Cmdr. The USA does not recognize China’s sovereignty over the islands, and treats the waters surrounding them as worldwide, while China claims the area is part of a military exclusion zone that it controls.

The US officials also tell the Journal that the military ships aren’t seen as behaving in a threatening way. China is set to hold a massive military parade this week featuring some 12,000 troops this week, marking the 70 years since World War II ended in Asia.

A respected analyst says that the presence of the ships in the Bering Sea was designed to send a message to Washington about China’s growing military might.

“Chinese leaders have clearly recognized that the resources that may be in the Arctic, the sea lines of communications that transit through the Arctic passageways that may open up as the ice melts are of tremendous potential value to China”, he said.

Recently, Chinese commercial ships have increased their trips in the Arctic Ocean in order to save on shipping costs.

Chinese officials have complained in the past that the U.S.is meddling in their affairs by flying military jets near a chain of islands known as the Spratlys in the South China Sea. The council’s members are the eight Arctic states: Canada, Denmark, Finland, Iceland, Norway, Russia, Sweden and the United States.

A White House spokesman said that no threatening activity had been witnessed and that the ships were in worldwide waters.

Such a naval force would serve the dual purposes of allowing China to protect its vital trade routes while also allowing it to project force far beyond its coastline.