U.S. Senator Edward Kennedy, one of the longest-serving senators in U.S. history and a towering figure in the Democratic Party, died at age 77.

Here are some reactions to the news:

IN THE UNITED STATES:

KENNEDY FAMILY STATEMENT - We've lost the irreplaceable center of our family and joyous light in our lives, but the inspiration of his faith, optimism, and perseverance will live on in our hearts forever. He loved this country and devoted his life to serving it. He always believed that our best days were still ahead, but it's hard to imagine any of them without him.

PRESIDENT BARACK OBAMA - Michelle and I were heartbroken to learn this morning of the death of our dear friend, Senator Ted Kennedy. For five decades, virtually every major piece of legislation to advance the civil rights, health and economic well being of the American people bore his name and resulted from his efforts. ... 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 United States Senator of our time.

US SENATE MAJORITY LEADER HARRY REID - It was the thrill of my lifetime to work with Ted Kennedy. He was a friend, the model of public service and an American icon. As we mourn his loss, we rededicate ourselves to the causes for which he so dutifully dedicated his life. Senator Kennedy's legacy stands with the greatest, the most devoted, the most patriotic men and women to ever serve in these halls .... The liberal lion's mighty roar may now fall silent, but his dream shall never die.

NANCY PELOSI, DEMOCRATIC SPEAKER OF THE HOUSE - Rooted in his deep patriotism, his abiding faith, and his deep concern for the least among us, no one has done more than Senator Kennedy to educate our children, care for our seniors, and ensure equality for all Americans.

FORMER PRESIDENT JIMMY CARTER, whom Kennedy challenged unsuccessfully for the Democratic presidential nomination in 1980 - I think that among all the members of our U.S. Senate and the Congress of the United States he has been pre-eminent. He has been a staunch and honest and open and very able to express his views to the American people, and my own hope is that his deep commitment to a comprehensive health plan in our country will be honored now by his contemporaries, by his peers, in the near future.

CALIFORNIA GOVERNOR ARNOLD SCHWARZENEGGER, husband of Kennedy's niece Maria Shriver and a Republican, - He was known to the world as the Lion of the Senate, a champion of social justice and a political icon .... Teddy inspired our country through his dedication to health care reform, his commitment to social justice, and his devotion to a life of public service.

SENATOR ORRIN HATCH, REPUBLICAN OF UTAH - Ted Kennedy was an iconic, larger than life United States senator whose influence cannot be overstated. Many have come before, and many will come after, but Ted Kennedy's name will always be remembered as someone who lived and breathed the United States Senate and the work completed within its chamber.

FORMER US FIRST LADY NANCY REAGAN - Given our political differences, people are sometimes surprised by how close Ronnie and I have been to the Kennedy family. In recent years, Ted and I found our common ground in stem cell research, and I considered him an ally and a dear friend. I will miss him.

FOREIGN REACTION

BRITISH PRIME MINISTER GORDON BROWN - Senator Edward Kennedy will be mourned not just in America but in every continent. He is admired around the world as the Senator of Senators. He led the world in championing children's education and health care, and believed that every single child should have the chance to realize their potential to the full.

IRISH PRIME MINISTER BRIAN COWEN - Ted hailed from a most famous Irish-American family, and through his own endeavors and achievement, he has added further luster to the reputation of a great family ... In good days and bad, Ted Kennedy worked valiantly for the cause of peace on this island. He played a particularly important role in the formative days of the Northern Ireland Peace Process in the early to mid-1990s. ... Today, America has lost a great and respected statesman and Ireland has lost a long-standing and true friend.

FORMER BRITISH PRIME MINISTER TONY BLAIR - Senator Kennedy was a figure who inspired admiration, respect and devotion not just in America but around the world. He was a true public servant committed to the values of fairness, justice and opportunity.

ISRAELI PRIME MINISTER BENJAMIN NETANYAHU - (Senator) Kennedy has been a friend for 30 years, a great American patriot, a great champion of a better world, a great friend of Israel. He will be sorely missed.

ITALIAN PRESIDENT GIORGIO NAPOLITANO - A great protagonist of American public life has disappeared, a combative and coherent interpreter of the role of the U.S. Congress, a constant defender of that democratic balance and the guarantees of freedom which have given strength and prestige to his country. In this sense, Ted Kennedy has left a profound mark and deserves the homage of the free world.