TAIPEI - Taiwan's president met briefly on Thursday with a Chinese official in one of the highest-level contacts between the two sides since the Chinese civil war, while thousands of protesters clashed with riot police outside.

President Ma Ying-jeou shook hands and exchanged gifts with China's top Taiwan affairs negotiator, Chen Yunlin, who has already signed agreements opening up trade and transport between the two sides that in past years have edged to the brink of war.

Outside the presidential office, at least 10,000 protesters wearing "Taiwan is my country" ribbons shouted abuse, telling Chen to leave and Ma to step down.

"What cannot be denied is that between the two sides some differences and challenges still exist, especially on the
issues of Taiwan's security and international space," Ma said at the five-minute meeting with the Chinese leader.

According to security-conscious Taipei, China has more than 1,000 missiles aimed at the island just across the Taiwan Strait, one the world's most dangerous flashpoints.

Beijing, with about 170 diplomatic allies compared with Taiwan's 23, also bars the island from international organisations such as the United Nations, which requires statehood as a precondition for membership.

Communist China, a permanent member of the U.N. Security Council, has claimed sovereignty over self-ruled Taiwan since 1949 and has vowed to bring the island of 23 million people under its rule, by force if necessary.

Ma's predecessor advocated formal independence from China, outraging Beijing and freezing high-level contacts.

Warming trend

Ma told Chen he wanted to see more high-level exchanges and said the two sides should not "mutually deny" each other's existence. Chen's reply to Ma was inaudible to the audience.

"The meeting is highly symbolic, mainly to show a parity between the two sides," said Chao Chien-min, a politicalscience professor at National Cheng Chi University in Taipei.

Ma is under pressure at home to be politically tough on China while improving the island's sagging economy by getting a piece of the other side's booming markets.

Negotiators from Taiwan and China signed a series of deals on Tuesday expanding daily direct flights and agreeing on new air routes, direct cargo shipments and direct postal services.

But protesters have been camping out in the streets since Chen arrived on Monday, accusing Ma of selling out.

"I'm here to resist China," said Lin Ting-fung, a 52-year-old from Chungli city, just south of the capital."I don't know how to express myself clearly, but I just don't feel comfortable when Chen Yunlin is here."

Late on Wednesday, protesters mobbed a Taipei hotel where Chen had attended a banquet. Ma brought forward the time of his historic meeting with Chen on Thursday to avoid further trouble.

He defended the deals with China and condemned the overnight protests, which blocked Chen's exit from the hotel.

"You can't say that love for Taiwan will become the selling out of Taiwan," he said.

Chen also attended a ceremony on Thursday to mark an upcoming exchange of two giant pandas, a gift symbolic of China, for an indigenous goat and deer from Taiwan.

He is set to watch "Cape No. 7", a made-in-Taiwan blockbuster movie that has become a source of pride for the
island and which is expected to be shown in China, the first Taiwan film to be allowed a screening in years.

Chen returns to China on Friday.