VIETNAM'S most powerful leader yesterday called for 'younger blood' in Hanoi's ruling Communist Party to help lead the country through a future of dramatic change. Do Muoi, party General Secretary and Politburo chairman, said he hoped to see younger members moving into more powerful positions at next year's eighth congress. 'We need new blood and it should be mixed with that of the veterans to lead our country,' Mr Muoi, now 78, said, adding the party had to do more to attract younger, more independent members. 'It's not good to have all new blood but you do need a balance,' he said. His rare comments followed a call by Prime Minister Vo Van Kiet opening Vietnam's National Assembly yesterday to protect the country against negative foreign influences now that its doors were open. Mr Kiet also warned more needed to be done to tackle rampant crime, including corruption, smuggling and tax evasion. Mr Muoi said he feared Vietnam's Government was not yet strong enough to beat corruption and new ways had to be found to make society more equal as changes took hold. Market forces could not be allowed to divide or weaken culture and morality, as they had done in the United States, he said. 'The gap between rich and poor is becoming polarised . . . any social divisions could be very serious,' he said. When asked by the South China Morning Post if he feared side-effects from Vietnam's new international ties, Mr Muoi said Hanoi would always keep its independence as it sought new links. 'Independence and sovereignty is the central core of the country . . . We want peace and we must make sure we have many friends.' Mr Kiet told the assembly members to remain 'vigilant' as Vietnam improved links with the US and the Association of South East Asian Nations. 'In our open exchanges with other sides we have to be vigilant to preserve our cultural instinct, to defend national security and to protect our natural and social environment,' he said. 'We must upgrade the spirit of the nation, patriotism and economics. All must be upgraded. 'They all must be well-defined in each act in our relations with the outside world. This is posing unique demands. We must protect our interests, reduce our losses but constantly co-operate and accept acute competition right now.' His speech came amid more rigid enforcement of regulations governing foreigners' activities in Vietnam and signals of tougher foreign investment rules. Previous state-of-the-nation addresses highlighted the economy, the fight against corruption and social evils but diplomats said it was clear sovereignty and shoring-up party strength were now the priority. Mr Kiet said economic crimes were costing the country millions and posed a big threat, reducing revenue and destroying the environment. He urged assembly members to work for a leaner, more effective government while improving the tax system. The assembly, Vietnam's chief lawmaking body, is to debate policy behind closed doors for the next month. Laws governing the reform of Vietnam's tangled bureaucracy and a new court allowing citizens to take on the Government are expected to be passed. A sweeping civil code is also up for discussion by the assembly, which comprises both party and non-party elected members. It will sit again next March.