TAIPEI (AFP) - A US congressional group paid a rare visit to a Taiwan naval base on Sunday, a military source said, raising speculation about efforts to revive a US deal to provide the island with eight submarines.

The delegation, led by Edward Royce who is chairman of the US House Committee on Foreign Affairs, arrived on Saturday as part of a visit to East Asia, according to the de facto US embassy, the American Institute in Taiwan.

"While in Taiwan, the delegation will meet with senior leaders to discuss US-Taiwan relations, trade and other significant issues," it said in a statement.

The delegation visited the Tsoying naval base in the south for a briefing and boarded a warship Sunday before meeting Kaohsiung city mayor Chen Chu, the military source said, without providing details.

The United States remains the leading arms supplier to Taiwan despite switching diplomatic recognition from Taipei to Beijing in 1979.

In April 2001 then-President George W. Bush approved the sale of eight conventional submarines as part of Washington's most comprehensive arms package for the island since 1992.

Since then, however, there has been little progress in filling the order.

The United States has not built conventional submarines for more than 40 years and Germany and Spain reportedly declined to offer their designs for fear of offending China.

"The military will voice its desire to obtain the submarines while briefing the US congressional delegation, given Taiwan's pressing need," the Liberty Times quoted an unidentified officer as saying.

The Taiwanese navy currently has four submarines, but only two of them - Dutch-built - could be deployed in the event of war.

The other two were built by the United States in the 1940s.

Tensions between Taiwan and China have eased markedly since President Ma Ying-jeou came to power on a platform of strengthening trade links and allowing more Chinese tourists to visit. Ma was re-elected in January.

But Taiwan, which has governed itself since 1949, still sees the need to modernise its armed forces because China regards the island as part of its territory awaiting reunification, by force if necessary.