Officials in the Falkland Islands said they would never forget Thatcher's decision to defend the South Atlantic territory in 1982.
"Her friendship and support will be sorely missed, and we will always be thankful for all that she did for us," said Mike Summers of the Falkland Islands Legislative Assembly.
The United Kingdom and Argentina went to war over the territory in 1982 after the then-military government in Argentina landed troops on the islands. Argentina put its death toll from the conflict at around 645. Britain says its civil and military losses amounted to 255.
Over the past year or more, rhetoric between the two countries over the islands has escalated sharply, and Argentina's state-run Telam news agency offered an unflinching look Monday at the South American country's take on Thatcher's legacy.
Articles described her as "a symbol of war," "an expression of inequality" and "a great destroyer."
For British filmmaker Ken Loach, known for his gritty social critiques, Thatcher was "the most divisive and destructive prime minister of modern times."
"Mass unemployment, factory closures, communities destroyed -- this is her legacy. She was a fighter and her enemy was the British working class," he said.
"Her victories were aided by the politically corrupt leaders of the Labour Party and of many trades unions. It is because of policies begun by her that we are in this mess today."
Her final years
Thatcher was ultimately brought down, not by British voters, but by her own Conservative Party.
Having lost much support over her policy on Europe, Thatcher was finally forced to resign in 1990 during an internal leadership struggle after she introduced an unpopular tax that led to rioting in the streets.
Despite her painful exit, she remained involved in British politics for the next decade or so. She was named Baroness Thatcher of Kesteven after leaving office and served in the House of Lords.
Her wider influence on policy and politicians continues to this day.
She retired from public life after a stroke in 2002 and suffered several smaller strokes after that. Her husband, Denis, died in June 2003.