US President Barack Obama said Wednesday he was “heartbroken” over the death of Sen. Edward Kennedy, saying the liberal icon's demise closed an epic chapter in US political life. “Michelle and I were heartbroken to learn this morning of the death of our dear friend, Senator Ted Kennedy,” Obama said in a statement. The president was to address the American people at 8:30 A.M. (1230 GMT) from the well-heeled east coast resort of Martha's Vineyard where he was spending his vacation, the White House said. “An important chapter in our history has come to an end. Our country has lost a great leader, who picked up the torch of his fallen brothers and became the greatest US Senator of our time,” Obama's statement said. “I cherished his confidence and momentous support in my race for the presidency,” Obama added, noting that Kennedy broke with former allies Hillary and Bill Clinton to make an early endorsement of his run for the White House. Former President George H.W. Bush spoke for himself and his son, former President George W. Bush, in expressing sympathies from members of the Republican Party. “While we didn't see eye to eye on many political issues through the years, I always respected his steadfast public service,” said a statement issued by the elder Bush, who noted that his library gave the senator a public service award in 2003. Tributes poured in for Senator Kennedy with world leaders hailing “a great American” who was a tireless campaigner for peace and social welfare. “Senator Edward Kennedy will be mourned not just in America but in every continent,” Britain's Prime Minister Gordon Brown said in a statement. The Kennedy family has close ties with Ireland. Kennedy's great-grandfather, Patrick Kennedy, emigrated from County Wexford in the 1840s, while his sister Jean Kennedy Smith was US ambassador to Ireland from 1993 to 1998. “Ted hailed from a most famous Irish-American family, and through his own endeavours and achievement, he has added further lustre to the reputation of a great family,” said Irish Prime Minister Brian Cowen. German Chancellor Angela Merkel described Kennedy as “an extraordinary personality in American politics” who had demonstrated a “firm and resolute commitment to peace and justice.” Nelson Mandela's office mourned the death of US Senator Edward Kennedy, paying tribute to a “champion of democracy” for supporting South Africa's anti-apartheid struggle. “We mourn, with his family, and the United States of America, the loss of a champion of democracy and civil rights,” Nelson Mandela Foundation chief executive Achmat Dangor said.