Taiwan's president Thursday defended a historic summit with China as the first step to normalising relations between the leaders, as opponents wary over a rapprochement after decades of hostility accused him of selling out the island.

Ma Ying-jeou will meet with his Chinese counterpart Xi Jinping in Singapore on Saturday, in a dramatic recognition of a seven-year period of warming relations which has raised fears self-ruled Taiwan's security may be at stake.

Ma said the meeting was to ensure the future of cross-strait relations and would also be a chance for Taiwan to come in from the cold internationally, where few countries recognise it as a state.

It will be the first time leaders from the two sides, separated by the narrow Taiwan Strait, will have met since their split at the end of a civil war on the mainland in 1949, which left Taiwan to forge its own identity as a democracy.

In an address to the nation, Ma hailed the meeting as being "for the welfare of the next generation".

"Both sides of the Strait should work towards lowering hostility... This is the first step towards normalisation of meetings between the leaders," he said.

Taiwan lost its United Nations seat to China in 1971 and only 22 states formally recognise the island, which has led to marginalisation on the global stage, a key point of resentment for Taiwanese.

"Taiwan has for quite some time run into many difficulties participating in international events. We receive this feedback from the public frequently, such as from NGOs," said Ma.

"Therefore we will raise this issue... in order to come to some agreement for greater international space for Taiwan."

But the summit has been slammed by opponents who say Ma is trying to influence presidential elections in January, which the ruling Beijing-friendly Kuomintang (KMT) is set to lose.

Both Ma and his party have seen support plummet partly due to anti-China sentiment in Taiwan as concerns grow over Beijing's influence.

"We're angry that Ma is going to sell out Taiwan," said Hsu Ya-chi, spokeswoman for the pro-independence Taiwan Solidarity Union, one of the opposition parties that suspect some sort of secret deal between Ma and Xi.

- Renegade province -

Although nominally rivals, the two sides have become tightly linked, with the launch of direct flights, trade deals and a tourism boom in recent years as they forged previously unthinkable ties.

But despite the many decades of operating as a self-ruling economy with a fierce sense of identity, Beijing considers the island a renegade province awaiting reunification -- by force if necessary.

"The summit is not for the next election, it is for the welfare of the next generation," said Ma.

"I feel it is my duty to build a bridge for the two sides."

Ma said key ally the United States had been notified of the meeting in advance, but had played no role in arranging it.

The US, which is committed to defending the island -- its former cold war outpost -- against any Chinese aggression, has given a cautious welcome to the summit which will see the leaders speak publicly and behind closed doors before having dinner.

- Why now? -

While observers agree the meeting is a landmark moment, there are questions over why Beijing has agreed to do it now, having resisted Ma's previous attempts to organise a face-to-face.

As well as being a public show of support for the KMT ahead of the elections, it is seen by some as a move towards solidarity with a US ally at a time of simmering tension between Beijing and Washington.

Beijing's anger flared after the guided missile destroyer USS Lassen last week sailed close to artificial islands it has built in the disputed South China Sea, construction that has alarmed China's neighbours.

Ma came to power in 2008 promising prosperity through better ties with Beijing.

But many voters feel trade deals have benefited big business, not ordinary people, and observers say the KMT risks a backlash over the summit at the presidential elections.

Tsai Ing-wen of the Beijing-sceptic Democratic Progressive Party -- widely tipped to win the presidency -- said the meeting would "hurt Taiwan's democratic politics".

"The people will not allow him (Ma) to limit Taiwan's future purely for his own political credit," she said.

Ma confirmed there would be no agreement or joint statement between the two sides, a move analysts say is designed to assuage the nerves of the Taiwanese public.

The leaders will give individual press conferences after the meeting.

To avoid the risk of a protocol problem over the title "president", they will not use their official titles, instead addressing each other as "Mister".