The arrival of a high-tech Chinese scientific surveillance ship in Fiji on the same day as the Australian Navy visited was "purely a coincidence" according to China's ambassador, who has stridently rejected claims of spying.

On Saturday the ABC revealed Defence figures suspected the Chinese vessel was trying to snoop on Australian military activities during a brief visit to the Pacific nation.

HMAS Adelaide, with a contingent of US Marines on board, docked in the port of Suva as part of "Indo-Pacific Endeavour 18", a major maritime activity aimed at "building regional security and stability" in the South Pacific.

Shortly after, the Yuanwang 7, which is used to track and support Chinese Army satellites and intercontinental ballistic missiles, docked close to HMAS Adelaide.

China's ambassador to Fiji, Qian Bo, has rejected suggestions the ship was also sent to spy on the Australians, arguing the Yuanwang 7 had long been scheduled to visit Suva.

"This is purely a coincidence, it is not at all true that (the) Chinese Space Surveillance Ship is spying on the so-called Australian military ship," he told the Fiji Village newspaper.

"The Chinese ship is a scientific ship, the dates coming to the Suva Port is decided (a) long, long time ago," he added.

On Saturday the Commander of the Navy's Joint Task Group 661, Captain Jim Hutton, played down concerns about the presence of the Chinese surveillance ship but confirmed HMAS Adelaide and other Australian warships visiting Fiji would "take the appropriate security precautions".

Ambassador Qian said Beijing was hoping to build international relations and a "shared community" with all nations in the region.

"China is a friend to all, and an enemy to none, like the Fijians," he said.

"Our relationship with Fiji is a very strong and friendly relationship and China has a broader vision of ourselves in terms of foreign policy.

"Our relationship with Australia should also be friendly and a cooperative one, and it is very unfortunate that recently our relationship has experienced some difficulties — that was mainly due to the reasons what the Australian side should have understood."

Foreign Minister Julie Bishop also played down concerns about China's growing presence in the South Pacific.

"The Chinese Navy traverses international waters as the Australian navy does. We often are in the same port as other vessels from other countries and China is of course free to traverse the world as the Australian Navy is and free to be hosted in other countries.

"The fact that a Chinese vessel is in Fiji is of no concern, we often are in the same part of the world as the Chinese Navy and indeed many other navies," Ms Bishop said.