Ronald Reagan was laid to rest Friday night after a week of ceremony commemorating his life and times as the United States' 40th President.

His family and hundreds of friends were present in the grounds of the presidential library in Simi Valley, Calif., for the private burial service.

His wife Nancy was handed the Stars and Stripes that had been covering the presidential casket throughout the week by the Navy commander of the U.S.S. Ronald Reagan.

A tearful Mrs. Reagan lingered over the coffin with her children Michael, Patti and Ron.

"He is home now, he is free," Ron Reagan said in his eulogy at the sunset service.

"In his final letter to the American people, Dad wrote, `I now begin the journey that will lead me into the sunset of my life.' This evening, he has arrived."

But in a speech that contained many humorous references to the former actor and president's lighter side, Ron Reagan also recalled his father's penchant for pinching people's earlobes.

The ceremony was also attended by California Governor Arnold Schwarzenegger and his wife, and former British prime minister Margaret Thatcher.

Earlier Reagan's casket had been flown to California from Washington, following a state funeral attended by scores of current and former world leaders .

Ronald Reagan guided the United States through one of the most decisive decades in the 20th century, President George W. Bush said on Friday.

Speaking at Reagan's state funeral, Bush hailed Reagan as a leader who would "defend liberty wherever it was threatened."

Like his father and former Canadian prime minister Brian Mulroney, who both spoke ahead of him, Bush mixed his comments about Reagan the president with memories of the man.

"Our 40th president wore his title lightly and it fit like a white Stetson," Bush said.

Two former leaders who moved across the world stage alongside Reagan also paid tribute, hailing Reagan as the man who won the Cold War and transformed the world.

Mulroney said Reagan had "a rare and prized gift called leadership, that ineffable and sometimes magical quality that sets some men and women apart so that millions will follow them as they conjure up grand visions and invite their countrymen to dream big and exciting dreams."

"Ronald Reagan does not enter history tentatively; he does so with certainty and panache," Mulroney said. "At home and on the world stage, his were not the pallid etchings of a timorous politician. They were the bold strokes of a confident and accomplished leader."

The flag-draped casket of the former U.S. president arrived at the National Cathedral Friday morning for an interfaith service that included the Catholic, Jewish, Muslim and other religions. The state funeral was the first for a U.S. president in more than 30 years.

The tributes to Reagan began with a videotaped address from former British prime minister Margaret Thatcher, who said Reagan had "lifted up the world."

"He sought to mend America's wounded spirit, to restore the strength of the free world, and to free the slaves of communism. These were causes hard to accomplish and heavy with risk," Thatcher said.

"Yet they were pursued with almost a lightness of spirit."

Former president George Bush, who served as Reagan's vice-president, said Reagan had taught him and others by example.

"I learned kindness – we all did," said Bush. "I also learned courage – the nation did ...

"I learned decency – the whole world did."

Earlier, rain fell as an honour guard accompanied the casket and Reagan's family into the church.

Eight members of the military representing all branches of the forces carried the coffin into the church from the hearse that had brought it from the Capitol building.

A military band played Hail to the Chief as the casket moved past an honour guard on the stairs to the church.

Nancy Reagan accompanied the hearse in a separate car from the Capitol to the cathedral.

Earlier Friday morning, officials closed the doors to the rotunda after tens of thousands of people filed past the president's flag-draped coffin.

The body of Reagan lay in state for 35 hours in the rotunda of the Capitol building, during which time about 90,000 Americans filed past, some of them waiting hours in line for their chance to spend a few moments paying their respects.

The doors were closed shortly after 8 a.m., after officials extended the time to allow more people through.

Nancy Reagan spent a few moments with the casket Friday morning, which is being carried to the National Cathedral for a funeral the likes of which Washington hasn't seen since Lyndon Johnson died in 1973.

At the Cathedral, where demand for invitations far exceeded the 2,100 seats available, dozens of dignitaries from across the United States and around the world gathered.

Irish tenor Ronan Tynan sang Franz Schubert's Ave Maria.

Prince Charles sat next to Mulroney and his wife Mila in the cathedral.

Along with the first president Bush, the three other living ex-presidents were in the church: Bill Clinton, Jimmy Carter and Gerald Ford.

Dozens of current and former world leaders and government representatives attended. Canada was represented by Gov. Gen. Adrienne Clarkson.

Others in the cathedral included British Prime Minister Tony Blair, former Soviet president Mikhail Gorbachev, Afghan President Hamid Karzai, Italian Prime Minister Silvio Berlusconi and South African President Thabo Mbeki.

At noon, 21-gun salutes sounded at every U.S. military base around the world. At dusk, a global 50-gun salute will sound.