Taiwan’s Defense Ministry has sought to play down the presence of a US Navy ship in the southern port city of Kaohsiung, stressing the “non-military” nature of the port call as the Thomas G Thompson is a research vessel.

The ministry has gone so far as to urge the media to stop speculating about the ship’s mission or how it could relate to a proposed show of force in the Taiwan Strait by the US Navy.

Speculation is still rife about increased Taiwan-US military partnership after the US National Defense Authorization Act for fiscal year 2018 opened up the possibility of mutual visits by Taiwanese and US warships.

The 3,095-ton RV Thomas G Thompson, which operates under the Office of Naval Research of the US Navy, dropped anchor in the Port of Kaohsiung this week to replenish supplies and for R&R (rest and recuperation) for its crew. This is its fourth port call to Taiwan.

Taiwanese Defense Minister Yen De-fa said his ministry would always monitor every vessel that entered the island’s territorial waters.

A spokesman for the ministry also said the vessel’s mission was to exchange scientific data with oceanographers and atmospheric researchers at National Taiwan University.

However, a retired navy captain told the Taipei Times that the timing of the US vessel’s appearance in Taiwanese waters could contain a political message.

He said the ship could be equipped with remotely operated and autonomous underwater vehicles (AUVs) for conducting oceanographical surveys, essential for military navigation through a maritime region.

He added that the ship while en route to Fremantle, Australia, could have stopped in the Philippines instead of Kaohsiung for supplies.

China’s Taiwan Affairs Office has reiterated that it opposes any form of military contact between the US and Taiwan.

Chinese experts said on Wednesday that the US was testing Beijing’s red line and that the vessel “posed a threat to the Chinese navy” despite Taiwanese authorities stressing that the ship was there for scientific research only.

A vessel like Thomas G Thompson could be there to gather hydrological information of sea areas around the Chinese mainland and Taiwan for the use of US submarines, one expert said.