Berlin  - Chinese Vice-President Xi Jinping met Monday with Germany's Chancellor Angela Merkel, one day before both are to inaugurate this year's Frankfurt Book Fair, with China as guest of honour.

Their "intensive, 90-minute discussion in a particularly friendly atmosphere" covered Iran's nuclear programme, the upcoming climate change conference in Copenhagen and the state of China's economy, Merkel aides said in a statement.

In a foretaste of Germany's change of government, Xi also met at his hotel with Guido Westerwelle, leader of the Free Democrat Party (FDP), which is about to enter into government with Merkel's party. Westerwelle is tipped to become foreign minister.

Beijing has spent lavishly on a special display and artistic performances during the book fair, where special-guest status attracts the attention of the German arts media to the guest nation's books.

Beijing-Berlin relations have become even again after a period of strain in 2007, when China was upset at Merkel for meeting in her office with the Tibetan spiritual leader, the Dalai Lama. The Chinese occupied Tibet in 1951 and say it is an integral part of China.

However China's bid to shut dissident authors out of its official events programme has provoked anger among German commentators.

Last month Beijing insisted that two dissident authors not be invited to a pre-fair symposium in Frankfurt about modern Chinese literature. Chinese officials briefly walked out when they showed up anyway.

Amnesty International appealed Monday to Beijing to end censorship.

"Even if it is here as a guest, China must be constantly reminded that it needs to observe human rights," said Monika Lueke, secretary general of the German section of the human rights organization, in an interview with the German Press Agency dpa.

Lueke said China routinely prevented certain authors from publishing their writings or travelling abroad. It also censored what its people could read on the internet, she said in Berlin.

"They have a censorship authority with 30,000 employees that monitors the internet day and night," she said, demanding this cease.

"Of course one is polite to guests. But you are also frank with a guest: you don't mislead your guest. The Chinese have to be told that there are certain basics which need to be observed," she said.

Beijing is sending nearly 1,000 performers, authors and officials to Frankfurt for the special show.

The five-day fair, set to open its doors on Wednesday, is the world's biggest trade show in book publishing. Merkel is to declare it open at a Frankfurt ceremony on Tuesday evening with Xi in attendance.  dpa