PRESIDENT Jiang Zemin today becomes the most senior mainland official to ever visit Vietnam, touring Ho Chi Minh City and meeting members of the once-troubled ethnic Chinese community. Thousands of ethnic Chinese fled the city's Chinatown, Cholon, crying persecution in 1979 in a campaign said to have sparked China's violent but shortlived northern invasion. Reports that Mr Jiang is arriving in the south before the Hanoi has surprised many diplomats and observers, with several seeing it as a provocative move. 'Essentially Ho Chi Minh City is closer to Mr Jiang's last stop in Jakarta, so it makes sense to go there first,' said a source at the Chinese Embassy. 'We do not want to cause any trouble for Hanoi on this trip.' Mr Jiang, General Secretary of the Communist Party, is the first president ever to visit Vietnam. And while Vietnam's state and party welcomes will show a degree of warmth reserved only for Hanoi's former ideological allies, it will take a lot more to thaw a historical frost based on mutual mistrust and suspicion. Mr Jiang's visit is seen as the most significant step yet in a relationship only normalised three years ago. It comes at a time when tensions are high at several flashpoints in the Tonkin Gulf and South China Sea. Despite agreements last year that the situation must be solved peacefully, diplomatic exchanges have intensified amid several recent reports of incursions and naval standoffs. A source at the Chinese Embassy said Mr Jiang would avoid the Spratly Islands debate for fear of undermining and 'overall significance' attached to his visit. Tensions are currently running high over a string of alleged incursions by Chinese fishing boats in the Tonkin Gulf area, while the Vietnamese navy has stepped up patrol of it Tu Chinh oil field in the Spratly Islands, claimed also by China. Chinese exploration vessels frequently tour the area, Beijing having awarded rights to an obscure Denver oil company. However, Mr Jiang is tipped to keep to party-to-party platitudes in meetings with his Vietnamese counterpart Do Muoi, Prime Minister Vo Van Kiet and President Le Duc Anh. He will also meet former communist revolutionaries such as Pham Van Dong, now in his 90s, and People's Committee representatives in both cities. But a powerful 150-strong delegation of Beijing officials, headed by Foreign Minister Qian Qichen, are to cover unresolved land and sea territorial disputes in closed-door sessions. Trade is the only area expected to yield results. China may be widely seen in Hanoi as Vietnam's most important foreign neighbour but regulated trade lies crippled under a mass of smuggled goods now lining Hanoi's streets. Clothes, fake CDs and even cars are smuggled over the largely uncontrolled northern land border and both governments are keen to better control trade for mutual benefit.