Taipei: Taiwan had to use a mainland Chinese shipper to get vital materials to a $US100 million port it is building on a disputed island in the South China Sea last month after it couldn't find a local firm to do the job, Taiwanese officials said on Friday.

A coastguard official told Reuters the vessel from Shanghai Zhenhua Heavy Industries, a state-run company, was escorted by a Taiwanese patrol boat to Itu Aba island on what he called an unprecedented mission.

Itu Aba, also called Tai Ping. Credit:Wikimedia

China claims virtually all of the South China Sea and is at loggerheads with other claimants in the contested waters, particularly the Philippines and Vietnam.

Yet the willingness of Zhenhua Heavy to accept such a contract from Taiwan, which China regards as a renegade province, shows how Beijing is largely unfazed by the work on Itu Aba.