Cold War contemporaries and a later generation of US leaders, as well as New Zealand Prime Minister John Key, have hailed Margaret Thatcher as an icon of freedom and capitalism, after the Iron Lady and ex-prime minister died in London.
Thatcher's former spokesman, Tim Bell, confirmed the former prime minister had died on Monday morning of a stroke at the age of 87.
Prime Minister John Key said he had admired Thatcher.
"You had to admire a woman that had such courage of her convictions," he said shortly after landing in Shanghai on his trade mission to China.
"She faced very, very difficult times, difficult circumstances. She stood up for what she believed in. She was fiercely determined all the way through."
There would be people who agreed and disagreed with the direction in which she took Britain ''but what you cant question is that she was up against a very challenging set of circumstances on a number of fronts, she passionately believed in what she was doing and that passion showed all the way through".
He recalled some of the challenges she faced including the bombing campaigns by the Irish Republic Army and the war against Argentina over the Falkland Islands.
"She will be remembered as a very strong and determined leader that faced some real challenges -obviously the conflict with the Falklands, the conflict with the IRA and tremendous economic challenges that Great Britain faced
"I think she has left a strong and permanent legacy for Great Britain. The challenges she faced were quite unique at the time. She was very determined as a leader but she believed passionately in what she was doing and she'll be missed by many people in Britain."
Former presidents George Bush and Jimmy Carter, who worked with Thatcher in the late- and post-Cold War period, paid quick tribute, as did President Barack Obama who was 29 and not even in politics when Thatcher lost power in 1990.
The uniform respect for Thatcher on the American side of the Atlantic reflected the uniformly admired legacy she left in the United States compared to the more contested one for which she is remembered in Britain.
Thatcher is most recalled in the United States for her close relationship with former president Ronald Reagan during the 1980s, which was seen as instrumental in winning the Cold War over the former Soviet Union.
Reagan's widow Nancy declared the two leaders were "political soul mates, committed to freedom and resolved to end communism".
"The world has lost a true champion of freedom and democracy," she said.
Bush senior, president when Thatcher was toppled by her own Conservative party during the runup to the 1990-91 Gulf War against Iraq, praised Thatcher as "one of the 20th Century's fiercest advocates of freedom and free markets - a leader of rare character who carried high the banner of her convictions".
"America has lost one of the staunchest allies we have ever known; and yet we have confidence that her sterling record of accomplishment will inspire future generations," he said.
Obama issued a statement paying tribute to Thatcher 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."
"With the passing of Baroness Margaret Thatcher, the world has lost one of the great champions of freedom and liberty, and America has lost a true friend," Obama said.
The US president, father of two daughters, also noted that Thatcher, as Britain's first woman prime minister, showed there was no "glass ceiling" that could not be shattered.
Former president Jimmy Carter, who was in the White House when Thatcher became prime minister in 1979, said his former counterpart was a "strong ally for peace and human rights".
He said Thatcher was instrumental in framing a stronger NATO alliance and efforts to bring US hostages home from Iran.
In recent years, Thatcher became an icon for a new generation of US politicians, especially conservative Republicans, who admired her tough and unapologetic persona on the world stage and embrace of market principles.
Former Republican vice presidential candidate Sarah Palin said Thatcher's legacy will live forever.
"She was a trailblazer like no other. We lost an icon, but her legacy, as solid as iron, will live on in perpetuity," Palin said in a Facebook Post.
Thatcher is also seen as a pillar of revived conservative politics, also embodied by Reagan, on Capitol Hill.
"Thatcher reshaped Britain from the state of economic and social turmoil in which she found it to a place of opportunity and promise during three terms in office," said Republican Senate Minority Leader Mitch McConnell.
"She boldly reasserted her nation's strength in foreign affairs, and she became an iconic symbol of the transformative power of conservative ideas."
House of Representatives Speaker John Boehner praised Thatcher as "the greatest peacetime prime minister in British history".
"Margaret Thatcher, a grocer's daughter, stared down elites, union bosses, and communists to win three consecutive elections, establish conservative principles in Western Europe, and bring down the Iron Curtain," Boehner said.
- AFP, NZ Herald