PARIS (AFP) - World leaders hailed Barack Obama's triumph Wednesday in the US presidential election as the dawn of a new era and called for the global superpower to change the way it does business. But within hours of Obama's victory speech, Russia announced it would be aiming short-range missiles at the US missile shield in Europe, a sharp reminder of the challenges awaiting the first black US president. Nothing however could stop the wave of optimism that spread out from the United States after Obama's victory over Republican rival John McCain. South Africa's iconic first black leader Nelson Mandela wrote in a message to Obama: "Your victory has demonstrated that no person anywhere in the world should not dare to dream of wanting to change the world for a better place. "We wish you strength and fortitude in the challenging days and years that lie ahead," he added. President Mwai Kibaki, who has declared a national holiday on Thursday to mark Obama's victory, said: "This is a momentous day not only in the history of the United States of America, but also for us in Kenya." Pope Benedict XVI sent a telegram of congratulations to Obama to hail the "historic occasion". French President Nicolas Sarkozy extended his "warmest congratulations" to the 47-year-old Democratic senator. "By choosing you, the American people have chosen change, openness and optimism," added Sarkozy. British Prime Minister Gordon Brown welcomed the victory as an historic moment. China's President Hu Jintao said in a written message: "In a new historical era, I look forward to... taking our bilateral relationship of constructive cooperation to a new level." Japanese Prime Minister Taro Aso pledged to work with the new US leader to strengthen relations, while Indian Premier Manmohan Singh called it an "extraordinary" victory. Australian Prime Minister Kevin Rudd referred to Martin Luther King's landmark "I have a dream" speech for equality 45 years ago. "Today what America has done is turn that dream into a reality," he said. European Commission President Jose Manuel Barroso said in a statement: "This is a time for a renewed commitment between Europe and the United States of America." Russian President Dmitry Medvedev, who was himself elected president in March, called for "constructive dialogue" in a message to Obama. Earlier however, in his first state-of-the-nation address, he announced that short-range Iskander missiles would be based in the western territory of Kaliningrad to "neutralise" US missile defence plans. With wars in Iraq and Afghanistan heading White House priorities abroad, there were also calls to rethink the US "War on Terror" launched by US President George W. Bush after the September 11, 2001 attacks. Obama's election would not lead to a quick US disengagement from Iraq, Iraqi Foreign Minister Hoshyar Zebari said. "We don't think there will be change in policy overnight. There won't be quick disengagement here. A great deal is at stake here," Zebari told AFP. Iranian Foreign Minister Manouchehr Mottaki said the result showed that Americans wanted "basic changes in US foreign and domestic policy," the official IRNA news agency reported. "We hope the new US government can fulfil its people's demand to distance itself from the present statesmen's wrong approaches," he added. Outgoing Israeli Prime Minister Ehud Olmert said he was certain US-Israeli ties would strengthen under Obama. "Israeli-US relations are a special relationship based on values and common interest, with tight cooperation," he said in a statement. Venezuelan President Hugo Chavez, a vociferous critic of the Bush administration, called in a statement for new relations "between our countries and with our region, on a basis of respect of sovereignty, equality and true cooperation."