"We have had contact with Chinese authorities about these concerning reports," US State Department spokeswoman Victoria Nuland told reporters.

Nuland said Washington was not in a position to confirm the reports but "we've made inquiries, we've expressed our concern should there be any sense of reprisal etc."

Chen on Thursday accused authorities in his home province in eastern China of seeking revenge for his escape by detaining his nephew and threatening other relatives.

Chen, whose daring flight from house arrest to the US embassy in Beijing sparked a diplomatic crisis, said his nephew Chen Kegui was in police custody in Yinan county in Shandong province after attacking an intruder last month.

Local villagers and Internet reports have said the intruder was a local official angered by Chen's escape.

Chen Kegui went on the run following the incident in late April and was later detained. His wife has been missing for the past few days, Chen said.

Faymann was scheduled to meet with the exiled Tibetan spiritual leader alongside Vienna Archbishop Christoph Schoenborn, the chancellor's office said, specifying however that this would occur "in a religious context."

A meeting between Spindelegger, who is also foreign minister, and the Dalai Lama was meanwhile "in the works," spokesman Alexander Schallenberg said, adding that the Chinese authorities had been informed.

No encounter however was planned with President Heinz Fischer.

In 2007, talks between the Dalai Lama and then-chancellor Alfred Gusenbauer prompted protests from the Chinese authorities and a minor rift in bilateral ties.

Beijing accuses the Dalai Lama of seeking the independence of Tibet, which it claims as its own.

The Tibetan leader's visit also comes after Austria last year celebrated 40 years of diplomatic ties with China, prompting a raft of business deals and a wave of high-level visits in both directions, culminating in a trip to Vienna by Chinese President Hu Jintao in October.

During his upcoming visit to Austria, the Dalai Lama will give a series of talks and seminars around the country.

Over the years, the Tibetan leader has paid regular visits to the alpine country, including to see his late friend the Austrian alpinist Heinrich Harrer, whose autobiography inspired the 1999 film "Seven Years in Tibet" with Brad Pitt.