State Councillor Tang Jiaxuan left for the United States yesterday for a goodwill visit that will pave the way for a presidential summit between the two countries scheduled for September. Mr Tang would address issues including North Korea's nuclear programme and the recent revaluation of the yuan with US counterparts, international-relations analysts said. US President George W. Bush has reportedly invited President Hu Jintao to visit his ranch in Crawford, Texas, in September. 'This is a positive gesture which indicates Bush feels comfortable with President Hu, and both sides are looking forward to exploring the potential upside of the relationship,' said Ni Feng , director of the American Studies Institute at the Chinese Academy of Social Sciences. With the tension over the value of the Chinese currency easing after last week's 2.1 per cent appreciation of the yuan, Mr Hu and Mr Bush would focus more on how to deal with North Korea and how to co-operate in the fight against global terrorism, the analysts said. 'The yuan is still an issue sitting between the two countries since Beijing only revalued it by a small margin - not enough to make a dent in the US trade deficit - but it's not that confrontational any more since Beijing has shown its commitment to currency reform,' said Shen Jiru , a senior researcher with the academy's World Economics and Politics Institute. Mr Tang set off for Washington on the same day that six-party talks on North Korea's nuclear ambitions resumed in Beijing after a long break. 'Security issues will occupy a great deal of time at the summit talks between Hu and Bush, especially North Korea,' Professor Shen said. Analysts believe the September summit will be good for the Sino-US relationship, which they said was strong despite quarrels on issues ranging from China's textile exports to plans to reform the UN Security Council. 'There's a high level of communication and interaction between top officials from the two countries ... despite all the kinds of friction in the news,' Professor Ni said. 'This relationship seems to be getting institutionalised.'