The crash of two Vietnam War-era jets in Taiwan that killed three sparked calls for the US to sell the island new planes and save its pilots from "risking their lives" in old aircraft.

The defence ministry's plea for advanced aircraft to defend the exposed island from its giant neighbour China came as rescuers located the wreckage of the crashed jets in east Taiwan. All three pilots were killed.

An RF-5 surveillance aircraft and double-seated F-5F trainer vanished from radar screens 13 minutes after they took off on a training mission at 7:39 pm (1139 GMT) Tuesday from an airbase near Hualien, the defence ministry said.

The military confirmed Wednesday that rescuers had discovered debris and body parts where the two jets had apparently crashed into the side of a mountain.

Military authorities are still investigating the accident, but officers said it highlighted Taiwan's need to purchase new fighters to replace its decades-old, US-built F-5 fleet.

"This type of jet has served the air force for more than 35 years... We really don't want our pilots to fly them risking their lives," defence ministry spokesman David Lo told AFP.

The backbone of Taiwan's air force consists of some 60 F-5s, 126 Indigenous Defence Fighters, 146 US-made F-16 A/Bs and 56 French-made Mirage 2000-5s.

Taipei applied in 2007 to buy 66 F-16 C/D fighters, which have better radars and more powerful weapon systems than the F-16 A/Bs, in response to China's growing military muscle.

"We hope the United States will sell the F-16 C/Ds as soon as possible," Lo said.

Beijing is strongly opposed to such sales, and US magazine Defense News reported recently that Washington has told Taiwan it will not sell the jets, but both US and Taiwan officials have insisted no final decision has been made.

Washington recognizes Beijing rather than Taipei but remains a leading arms supplier to the island.

Ties between China and Taiwan have improved since Ma Ying-jeou of the China-friendly Kuomintang party came to power in 2008 on promises of ramping up trade links and allowing in more Chinese tourists.

But Beijing has refused to renounce the use of force against Taiwan even though the island has ruled itself for more than six decades since their split in 1949 at the end of a civil war.