A senior U.S. official has gone to China's Xinjiang Province to examine complaints about human rights abuses there. China has agreed to allow U.N. human rights experts to conduct research in the country. Assistant Secretary of State Lorne Craner left Wednesday for Xinjiang, China's vast northwestern province. In addition to giving a speech to university students. He will talk to officials there about the human rights situation.

Many human rights groups say China abuses individual rights as it tries to assimilate the ethnic Uighur Muslims and crush a separatist movement then.

Tuesday evening, Mr. Craner said the Chinese government promised to invite United Nations investigators to study allegations of torture, arbitrary detention and restraints on religious freedom in the country.

Mr. Craner told reporters in Beijing that China's invitations would be issued immediately and with no conditions attached.

China has in the past agreed to allow a visit by the U.N. investigator on torture. However, Beijing imposed included several conditions, such as not letting him choose which prisons to visit, and barring him from meeting with inmates without supervision.

Mr. Craner says this invitation is different because it is unconditional. He says the move indicates that China appears to be serious about improving its human rights record.

Also Tuesday, Chinese Foreign Ministry spokesman Liu Jianchao said that two days of human rights talks with Mr. Craner's delegation had narrowed differences between the two countries.

Mr. Liu says the discussion had enhanced understanding between Beijing and Washington. But he did not mention the invitation to U.N. human rights investigators.

Rights activists have criticized Sino-American human rights talks held in recent years for producing few concrete results. Many activists urge Washington to put more pressure on China to release political prisoners, such as two Tibetans given death sentences recently for their involvement with a series of bombings in western China.

Mr. Craner said Tuesday that his delegation raised the case of the Tibetans. He said he also inquired about Rebiya Kadeer, a Muslim Uighur businesswoman, who is serving a long prison term for sending newspapers to her husband abroad. In the past, China has often later released prisoners the United States has shown an interest in.

Some human rights groups say the United States has turned a blind eye to China's abuses in Xinjiang, in return for Beijing's cooperation in the war on terrorism. A few months ago, Washington placed a Uighur separatist group, accused of carrying out bombings in China, on its list of terror groups.