In her weekly podcast, Merkel said that China has close ties to Africa and "we will obviously talk about what we can do now to combat the appalling human rights violations in Sudan's Darfur region."

Merkel arrives in China on Monday and will meet President Hu Jintao, Premier Wen Jiabao as well as cultural and civil rights groups. She heads to Japan on Wednesday where she will talk to leaders there about climate change and economic issues.

Sudan, which has had a tense relationship with the West for some time now, expelled the European Union and Canadian envoys earlier this week after accusing them of "interfering" in the country's internal affairs.

However, EU envoy Kent Degerfelt has been given a reprieve by Sudan. Khartoum will allow to remain until his tenure expires next month, following an EU apology, according to a presidential adviser who spoke on Saturday.

China has substantial economic interests in the African nation and has been under pressure to do more to quell the violence there, which is estimated to have cost 200,000 lives and displaced around 2.5 million people.

Urged to be tough on China

On Saturday, Amnesty International called on Merkel to also address the top of human rights in China itself when she meets the country's leaders.

"We hope that Chancellor Merkel will speak forcefully about the disastrous human rights situation in China," said Barbara Lochbihler, secretary general of the human rights group's German section.

"The continued human rights violations in China are in strong contrast to the official pledges to improve the human rights situation," she told the DPA news agency.

She said she expected Chinese authorities to "continue their harassment of human rights campaigners" ahead of the Olympic Games that will take place in Beijing next year. There were also fears that journalists would be subjected to increased pressure before the games begin, she said.

The chancellor raised the issue of human rights and appealed for more democracy when she met Chinese leaders during a previous visit to the world's most populous nation.

Officials in Berlin say Merkel will not shy away from difficult areas this time and will bring up the topics of human rights and press freedom in her official talks in the Chinese capital. She is scheduled to meet Chinese journalists, but it is not clear which ones and whether these have been put under pressure by Chinese authorities.

Calling the human rights situation in China "catastrophic," Lochbihler pointed out that the death sentence can be imposed for around 70 different crimes, including drug possession and tax evasion.

Even the right of citizens to freedom of information is severely restricted, she said.

"If you key in the words human rights, democracy or Amnesty International in an Internet search engine in China you won't get a single response," Lochbihler said.