China reacted coolly to an invitation Tuesday by Taiwan's leader for President Hu Jintao (search) to visit the island, rejecting any official contact until the Taiwanese ruling party drops a clause in its constitution calling for formal independence.

The lukewarm response came hours after Beijing offered a pair of giant pandas to the people of Taiwan plus concessions on fruit imports and tourism as Taiwan's opposition leader capped a groundbreaking visit to the mainland.

"We have no exchanges with the Democratic Progressive Party (search) because its party constitution advocates the separation of Taiwan from the motherland," Wang Zaixi, a spokesman for the ruling Communist Party's Taiwan Work Office (search), told reporters.

Wang said Taiwanese President Chen Shui-bian's party must first endorse a 1992 declaration that the self-ruled island and the mainland are "one China" and "drop the independence clause from its constitution."

"So long as these conditions are met, we can resume dialogue and consultations with Chen Shui-bian and the DPP," Wang said at a news conference.

Earlier Tuesday, Chen said he would welcome Hu for a visit to Taiwan. While the invitation appeared to be a conciliatory move, Chen remained steadfast in his pro-independence stance.

"I hope (Hu) can come to see for himself whether Taiwan is a sovereign, independent country, and what our 23 million people have in mind," Chen said to Taiwanese reporters during a visit to Kiribati, a small Pacific ally of Taiwan.

After a historic eight-day visit, Lien Chan, head of Taiwan's opposition Nationalist Party, returned home Tuesday, calling his trip a "journey of peace." It was the highest-level contact between the two sides since the Nationalists fled to Taiwan after the 1949 communist conquest of the mainland.

The visit "finished very happily, smoothly and successfully," Lien told reporters before flying out of Shanghai. "We have been warmly received by the Central Committee of the Communist Party."

Beijing's parting gifts gave Lien something to take home with him to help deflect criticism from those in Taiwan who accuse him of selling out the island's interests.

His success could boost his party's platform of unification with China, while undermining Chen's independence-leaning policies. Beijing still claims that Taiwan is Chinese territory to be regained by force if necessary.

In March, the mainland's legislature passed an anti-secession law authorizing military action should Taiwan move toward formal independence — an action Chen said showed Beijing's lack of understanding.

"The problem with cross-strait relations is that the mainland doesn't have sufficient understanding of Taiwan, so they misjudged the situation," he said.

Lien began his trip in Nanjing, the capital when the Nationalists ruled China, and traveled to Beijing, Xi'an and Shanghai.

"Wherever we went, we were welcomed by citizens who came voluntarily to show their friendship," Lien said. "This is the most precious experience for us to remember for every member of the delegation."

He added: "We hope ... to be able to meet with everyone again."

China's decision to grant two pandas to "compatriots of Taiwan" was announced by Chen Yunlin, director of the Communist Party's Taiwan Work Office, the official Xinhua News Agency reported. It did not elaborate.

He also announced that China would soon allow mainland residents to travel to Taiwan as tourists and that Beijing would increase the number of species of fruit allowed to be brought in from the island from 12 to 18, Xinhua reported.

The offer of the giant pandas was widely expected in Taiwan — late last week, officials there already were bickering about what to name the animals. But some Taiwanese officials reacted with caution. A similar gesture by Beijing years ago was refused because Taipei feared it was part of a plot to foster unification.

One of the ruling Democratic Progressive Party's greatest concerns is that China will insist Taiwan accept the pandas as a local Chinese government rather than as a self-governing entity.

"If we accept the pandas that means we're admitting ourselves we're a local government," said DPP lawmaker Hsu Kuo-yung. "Our lovely next generation is more important than these two lovely animals."

But President Chen said the only thing that mattered was that Taiwan would have to respect international treaties on protected wildlife.