Image copyright AP Image caption Mr Ma defied criticism from Taiwan's ally the US when he visited Taiping/ Itu Aba

Outgoing Taiwanese President Ma Ying-jeou has visited a disputed island in the South China Sea, in a show of sovereignty over the territory.

The US and Vietnam have both criticised the trip, which Washington said could exacerbate tensions.

But Mr Ma said the US and Taiwan shared hopes of peace for the region.

Taiwan administers the island, which it calls Taiping but which is also known as Itu Aba. It is also claimed by China, the Philippines and Vietnam.

The US called Mr Ma's trip "extremely unhelpful".

But he said he had informed Washington of his trip a few days beforehand, and that he believed the two countries had the same goals for the South China Sea.

"We all hope for peace, hope there is no conflict or war," Mr Ma told reporters.

As well as the US and Vietnam, which said it "resolutely opposes" the visit, China too is unhappy about the trip. It said it had "undisputable authority" over islands in the South China Sea.

China sees Taiwan as a renegade province which will eventually be reunited with the mainland.

What is the South China Sea dispute?

This was Mr Ma's first visit to Tiaping/Itu Aba in his eight years as president.

Taiwan has been upgrading facilities on the island, where about 180 people live, most of them coastguard personnel.

Speaking on the island, he reiterated a call for peaceful coexistence with other countries who claimed it.

"All this evidence fully demonstrates that Taiping Island is able to sustain human habitation and an economic life of its own. Taiping Island is categorically not a rock, but an island," he said.

It is the largest natural island in the Spratly chain, although now thought to be only the fourth biggest overall, after China's large-scale land reclamation work on Mischief Reef, Fiery Cross Reef and Subi Reef.

Mr Ma, who has cultivated better ties with China, ends his term in May.

The Democratic Progressive Party (DPP), which will form the next administration, leans towards independence for Taiwan. Reuters reports that the DPP declined a request from Ma for them to send a representative along, saying Taiwan had a responsibility to maintain peace and stability in the area.

The Spratly archipelago has many overlapping territorial claims by nations bordering the South China Sea, which is claimed almost in entirety by China.

Malaysia and Brunei also have claims involving the Spratly islands, though not involving this particular island.