The November visit has been agreed in principle by China and the US.

Mr Hu's trip to the US, after attending the United Nations' 60th anniversary celebrations in New York, will be his first visit as a head of state since he took over the presidency from Jiang Zemin in 2003. Mr Hu visited the US in May 2002 when he was vice-president.

Sources said diplomats from the two nations were working out details of the presidential summits to ensure they would produce substantial results and progress on a series of bilateral and global issues.

It is understood the two leaders agreed to the visits on the sidelines of the Apec meeting in Chile last November.

The matter was again discussed during US Secretary of State Condoleezza Rice's visit to the mainland last week.

Foreign Minister Li Zhaoxing told a press conference two weeks ago that Mr Hu was likely to attend the UN celebration, but no official announcement has yet been made about the state visits.

The agreement on the timing of the visits comes at a time of strained Sino-US relations, which have been exacerbated by the recent passage of China's anti-secession law.

Washington said the law, which sanctions the use of force against Taiwan if it seeks formal independence, was unhelpful for cross-strait relations - a comment that triggered strong reaction from China.

In February, anti-US rhetoric was sparked in mainland media when the US and Japan issued a joint declaration on security arrangements listing Taiwan as a 'common strategic objective'.

More recently, the tone adopted by Dr Rice during her visit did little to calm the nerves of the central government leadership.

Mainland analysts believe the US is shifting its policy towards China by strengthening its alliance with Japan to check the mainland's influence in regional politics.

US efforts to prevent the European Union from lifting its arms embargo on China is another sticking point. There are signs the EU will again delay lifting the embargo under pressure from Washington.

However, diplomats said that both Beijing and Washington were keen to improve relations. They said Dr Rice's visit had produced a substantial result in achieving speedy progress on the summits.

The presidential visits have been much sought after by Beijing, which is eager to have a formal mechanism for discussing strategic interests with Washington.

One mainland scholar said China also hoped the visits would offset earlier impressions that China was focusing on its relations with Europe and Latin America, following a series of high profile visits to these regions by state leaders.

Additional reporting by Ray Cheung