The U.S. has been tracking the flotilla – made up of three combat ships, a resupply ship and an amphibious ship – for days.

While officials declined to detail when the ships were first spotted or their distance from the coast of Alaska, they explained that the vessels entered the area after moving toward the Aleutian Islands, which are controlled partially by the U.S. and Russian Federation.

U.S. government officials acknowledged the curious timing of the Chinese ships navigating in the waters near Alaska at a time when President Obama is there, but White House spokesman Josh Earnest said Beijing’s intent was still unclear.

The looks of the ships is yet the growing act upon of China’s fleet and overlapped along with a three-day go to by Obama in to Alaska as component of his achievements to elevate cognizance about global warming. Bill Urban, a Pentagon spokesman, who confirmed the presence of the Chinese ships.

China became a permanent observer to the Arctic Council in 2013 and has shown increased interest in the region’s energy reserves.

Officials say they have been monitoring the ships’ activities, but said they were operating in worldwide waters.

Shorter shipping routes across the Arctic Ocean would save Chinese companies time and money. The Wall Street Journal was first to report the sighting.

Chinese media said that the exercises, roughly 2,000 miles west of the Bering Sea, ended last week.

China this year boosted its defence spending in a bid to modernise its forces, including developing stealth fighters and anti-satellite missiles, a move that has unnerved the US and its allies in the Asia-Pacific region.

China on Thursday will assert its military might with a large parade commemorating the end of World War II.

Xi is expected to spend about a week in the United States during the second half of September.