US Democratic and Republican political figures joined on Wednesday in mourning the death of Senator Edward Kennedy, who passed away earlier in the day at 77 after a long-time struggle with cancer.

US Senator Ted Kennedy (D-MA) reacts after President Barack Obama signed H.R. 1388, the Edward M. Kennedy Serve America Act, at the SEED Public Charter School in Washington, April 21, 2009. [Xinhua]

Three hours after Kennedy died at his home in Massachusetts, President Barack Obama, who is currently taking a vacation in a vineyard in the state, issued a statement, saying his family was "heartbroken" at the news.

Obama was also set to make a statement at a press conference in the vineyard on Kennedy's death on Wednesday morning.

"An important chapter in our history has come to an end," he said in the statement. "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."

The president also thanked Senator Kennedy for "his wise counsel in the Senate" and "his confidence and momentous support in" the presidential race last year.

Kennedy was one of politicians who endorsed the then first-term senator from Illinois in the early phase of the presidential campaign in 2008, and he presented himself several times at Obama's rallies.

Even after being diagnosed with a brain tumor, Kennedy continued to serve at the Senate, pushing forward with the health care reform and other legislative measures.

"Kennedy's dream of quality health care for all Americans will be made real this year because of his leadership and his inspiration," said House Speaker Nancy Pelosi in a statement.

Former President Jimmy Carter, who beat Kennedy in the 1980 Democratic presidential nomination, called his old rival "an unwavering advocate for the millions of less fortunate in our country."

Carter also credited to Kennedy for "the courage and dignity he exhibited in his fight with cancer" which "was surpassed only by his lifelong commitment and service to his country."

Kennedy, who had represented the state of Massachusetts in the Senate for decades, was not only a model for his Democratic fellows, but also admired by those from his rival Republican Party, despite their political differences.

Former President George H.W. Bush issued a statement on behalf of himself and his son, former President George W. Bush, 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," he said. "Kennedy was a seminal figure in the US Senate -- a leader who answered the call to duty for some 47 years, and whose death closes a remarkable chapter in that body's history."

Nancy Reagan, the widow of former president Ronald Reagan, also shared the sentiments, saying "Ronnie (Ronald Reagan) and Ted could always find common ground, and they had great respect for one another."

As a relative, California Governor Arnold Schwarzenegger, who married Kennedy's niece, Maria Shriver, gave credit to the Senator for helping him with his Hollywood-to-politics career.

"I have personally benefited and grown from his experience and advice, and I know countless others have as well," he said in a statement.