Former British Prime Minister Margaret Thatcher has died at the age of 87.

Her spokesman, Lord Bell, said her family announced on April 8 with "great sadness" that “she had died peacefully following a stroke this morning."

Thatcher, who is credited with helping to pull down the Iron Curtain, had been in ill health for many months.

“We've lost a great leader, a great Prime Minister and a great Briton," British Prime Minister David Cameron said.

"Her legacy will be the fact that she served her country so well and she saved our country and that she showed immense courage in doing so, and people will be learning about what she did and her achievements in decades, probably centuries to come," Cameron told the BBC. "That's her legacy."

In Madrid, Cameron announced after the news broke that he was cutting short a visit to Spain. He had been due to leave for France late on April 8, but that trip was postponed.

The prime minister's office said Thatcher would receive a "Ceremonial" funeral with military honors at London's St. Paul's Cathedral. It will not be a state funeral.

Buckingham Palace announced that Queen Elizabeth II was saddened by Thatcher's death.

WATCH: Margaret Thatcher, the long-serving British prime minister who infuriated European allies, found a fellow believer in Ronald Reagan, and transformed her country by a ruthless dedication to free markets, has died.

Margaret Thatcher Through The Years

"She was a titan in British politics," Michael Howard, Conservative leader from 2003-05, told Sky News television. "I believe she saved our country, because when she took over in 1979, we were in a period of real economic decline and many thought the country was ungovernable. I believe she saved the country, she transformed our economy, and I think she will go down in history as one of our very greatest prime ministers."

World Reaction

U.S. President Barack Obama said in a written statement that America had lost a "true friend" and the world a champion of freedom and liberty.

"As an unapologetic supporter of our transatlantic alliance, she knew that with strength and resolve we could win the Cold War and extend freedom's promise," Obama said in the statement.

Russian President Vladimir Putin hailed Thatcher as “one of the most remarkable political figures of the modern world." He said she "made a significant contribution to the development of the Soviet-British and Russian-British ties, which we will always remember with gratitude."

In Brussels, European Commission President Jose Manuel Barroso called Thatcher a "great stateswoman" and "a circumspect yet engaged player in the European Union."

"She helped bring about the single market," Barroso said. "She was a leading player also in bringing into the European family the Central and Eastern European countries which were formerly behind the Iron Curtain."

Former Soviet leader and Nobel Peace Prize laureate Mikhail Gorbachev spoke to the Interfax news agency after hearing of the former prime minister's passing. "Margaret Thatcher was a great politician and a bright individual," he said. "She will do down in our memory and in history."

When Gorbachev became the leader of the Soviet Union in 1985, he visited Thatcher in Britain and she famously called him a "man you can do business with."

Thatcher was known as the "Iron Lady" and remains the only woman to have served as Britain's prime minister.

She led the Conservatives to three election victories, governing from 1979 to 1990. In 1992, she was appointed a peeress in the House of Lords with the title Baroness Thatcher.

Thatcher suffered from dementia and has appeared rarely in public in recent years.

Based on reporting by Reuters and AFP