The self-ruled island currently has diplomatic relations with just 12 countries worldwide, three of them in the Pacific -- Tuvalu, Republic of Palau and Marshall Islands.

The three warships known as the Dunmu Goodwill Fleet will travel there after circling Taiwan, stopping at various ports to showcase the soldiers' athletic talents.

On Saturday, they were docked at the coastal city of Keelung where spectators cheered on the marines and snapped selfies with uniformed students from Taiwan's naval academy joining the "friendship" tour.

"I think it allows more exposure for Taiwan when they visit places and perform," said Scott Lin, who drove from nearby Taipei.

"It will help with the situation that Taiwan is currently facing."

The navy's friendship tour is a yearly event, but this visit comes as tensions have soared between Taiwan and China, which claims the democratic island as part of its territory.

Concerns ballooned after the presidential election in January -- won by Vice President Lai Ching-te, who Beijing regards as a "dangerous separatist". In a post-election blow to Taiwan, the small Pacific nation of Nauru dropped diplomatic relations with Taipei in favour of Beijing.

Nauru was the 10th ally poached by Beijing during the eight-year administration of President Tsai Ing-wen, who has refused to acknowledge China's claim on Taiwan.

"As tensions are rising in the enemy situation, we hope to use this opportunity to put into practice the theories we have learned," said Chen Kuan-ting, a student of Taiwan's naval academy who will be on the warship as part of his graduation requirement.

The students will be taking part in trainings on the warships, "getting familiar with life on the ships and the rules to follow", he said.

An unfurled sign displayed by marines showcasing their martial arts skills read: "Support national defence, protect the homeland".

But not everyone visiting Keelung Harbour had cross-strait tensions on their minds.

"It's very rare that kids get to see a warship," said Jean Chen, who brought her son so that he could board the vessels.