He became the first cardinal from a western country to visit the mainland since relations between China and the Vatican turned frosty after a dispute over canonisation in October 2000.

Church sources on the mainland noted Cardinal McCarrick's visit to Beijing came after the US Congressional Executive Commission on China held a hearing titled 'Will Religion Flourish under China's New Leadership?'

US President George W. Bush has made religious persecution a leading issue in bilateral relations.

He raised the issue with former president Jiang Zemin in an Asia-Pacific Economic Co-operation forum meeting in October 2001 and again spoke out on religious freedom during his visit to the mainland in February last year.

US Deputy Assistant Secretary of State Randall Schriver testified in the US commission hearing that there were 'hopeful signs' of religious freedom on the mainland as a result of the change of leadership in November last year.

He said that positive developments suggested a possibility of increasingly tolerance for religious activities.

The commission said China was one of six countries with the worst records for violations of religious freedom. The others were Myamar, Iran, Iraq, Sudan and North Korea.

The subtle shift could have important implications in the relations between China and US. Cardinal McCarrick's visit could lead to a dialogue, sources said.

The US Commission on International Religious Freedom, at the invitation of the central government, is scheduled to visit the mainland this month.

Cardinal McCarrick is one of the most influential religious leaders in the United States. He is chancellor of the Catholic University of America and president of the Papal Foundation.

He has long been active in the international work of the church. In January 1998, he was one of three American clerics to visit the mainland to discuss religious freedom.

During his visit, Cardinal McCarrick was received by vice-premier Hui Liangyu in the Zhongnanhai government compound. Mr Hui, a Muslim, has taken up nationalities and religious affairs in addition to agriculture in his official portfolio.

Earlier he met the Bishop of Beijing, Michael Fu Tieshan, who is also vice-chairman of the Standing Committee of the Chinese National People's Congress, and visited the National Seminary on the outskirts of the capital.

The visit by Cardinal McCarrick coincided with criticism of Catholic leaders in Hong Kong.

In official Xinhua reports, an unnamed mainland Catholic leader complained to the visiting cardinal that 'certain Catholic leaders' in Hong Kong had become political stars at odds with their religious roles.

The Hong Kong based Union of Catholic Asian News reported that the criticism was widely interpreted as being directed at Bishop Joseph Zen Ze-kiun, the head of Hong Kong's Catholic diocese.

In the Xinhua report, Cardinal McCarrick was quoted as having agreed with the mainland Catholic leader that the line between religion and politics should not be crossed.

He was also quoted as agreeing with Bishop Fu, who expressed his concern about 'improper behaviour' standing in the way of improving relations.

Cardinal McCarrick declined to discuss details of the trip but later hinted that words had been put in his mouth.