Britain

Queen Elizabeth II

"The Queen was sad to hear the news of the death of Baroness Thatcher. Her Majesty will be sending a private message of sympathy to the family," her office said.

Prime Minister David Cameron

"It was with great sadness that I learned of the death of Lady Thatcher. We have lost a great leader, a great prime minister and a great Briton."

Tony Blair, former Labour prime minister

"Very few leaders get to change not only the political landscape of their country, but of the world. Margaret was such a leader. Her global impact was vast."

United States

President Barack Obama

He said Margaret Thatcher was both a great champion of freedom and an example to women everywhere. In a statement, Obama said she showed "our daughters that there is no glass ceiling that can't be shattered".

Russia

Mikhail Gorbachev

"Margaret Thatcher was a great politician and a bright individual. She will do down in our memory and in history," said the Nobel Peace Prize winner, who held frequent meetings with Thatcher at the end of the Cold War.

EU

European Commission head Jose Manuel Barroso

Barroso said she had been "a circumspect yet engaged player in the European Union" who "will be remembered for both her contributions to and her reserves about our common project".

AFP -Reuters