AMERICAN Secretary of State Warren Christopher urged Vietnamese students to take up the cause of freedom and democracy in an address expected to rile Vietnam's Communist Party leaders. 'Vietnam must free up its courts, press and economy to succeed,' Mr Christopher said in his longest speech since arriving in Hanoi to formalise ties. 'When you hear Americans talk about freedom and human rights, what we mean is that each of us ought to have the right to help shape our country's destiny, as well as our own. 'If Vietnam is to find an important place in the community of nations and attract investment, it should move beyond just opening its doors. 'The key success in this rapidly changing world is the freedom to own, to buy and to sell; the freedom to participate in the decisions that affect our lives,' he said. Mr Christopher, the first Secretary of State to visit Hanoi, is the only recent visiting statesman to push the freedom line so openly and strongly on Vietnamese soil. No opposition political parties exist openly in Vietnam, and all land remains property of the state. Both Hanoi and Washington have already sought to dampen expectations of how warm ties between the former enemies will be, and Mr Christopher's speech may signal an even deeper wedge. After praising Vietnam's leaders for recent market reforms, Mr Christopher warned that 'command economies' could not be 'taken apart' slowly - 'only one giant leap will get you across'. 'The rule of law and accountable government are the bedrock of stability and prosperity. The reality of Burma and North Korea tells us that repression entrenches poverty. 'Communications technology is pushing the expansion of freedom for the individual at the same time as it is shrinking the distances between nations. Governments cannot control this movement of ideas in the information age, even if they wanted to,' he said. His address follows a stream of articles in Vietnam's official state press outlining US domestic human rights abuses and criticising President Bill Clinton's recent references to 'extending the reach of freedom' in Vietnam. Just last week the army paper Quan Doi Nhan said: 'We welcome normalisation but we cannot agree with some points in the speech which hurt the noble sentiments and the pride of the Vietnamese people.' Mr Christopher's meetings with senior Vietnamese leaders - the party's General Secretary Do Muoi , Prime Minister Vo Van Kiet and Foreign Minister Nguyen Manh Cam - have already revealed different agendas. Vietnam has stressed economic links in a friendship based on non-interference and independence while Mr Christopher has emphasised human rights and the continued hunt for remains of the 1,615 US servicemen classed as 'missing in action'. Privately, even younger and less traditional party and government officials fear normalisation poses a new series of threats to Vietnam's independence. The US has yet to draw up a framework for future trade, tax and investment agreements, but work is set to start soon. Earlier yesterday, Mr Christopher opened the US Embassy in Hanoi, saying Washington was determined to 'remain engaged' in the Asia-Pacific. 'On this the 50th anniversary of the end of World War II and the 20th anniversary of the end of the Vietnamese War, the US engagement in this region is absolutely essential to our security and our prosperity as never before.'