David Cameron and the Argentinian president Cristina Kirchner were involved in bruising verbal exchanges on the margins of the G20 on Tuesday as she tried to force a package into his hand marked "UN Malvinas".
Cameron refused to take the package believing, according to his aides, that she was involved in "a media stunt" – a belief strengthened by the presence of TV cameras filming the incident.
An Argentinian government official described Cameron as "sour" for refusing the letter and the Argentinian foreign minister was critical of the prime minister.
The package was an A4 envelope, and its contents remain unknown. Cameron had sought out Kirchner at the margins of the G20 in an anteroom before the first working session got underway. They initially discussed the previous day's agenda, including central banks and the need for monetary activism.
Cameron then said: "I am not proposing a full discussion now on the Falklands, but I hope you noted they are holding a referendum and you should respect their views. We believe in self-determination and act as democrats here in the G20."
The translator was struggling to catch up with her comments, but British sources characterised her response as "ramblings about Spanish headlines, the UN and the Malvinas". At this point she produced her envelope. British officials said Cameron had been right to reject the envelope as proper diplomatic channels existed.
The attempt to put an envelope in Cameron's hand mirrored an effort by a group of young Falkland Islanders to invite Kirchner to sit down and discuss their homeland as she attended a UN conference in New York on colonialism on Thursday.
Britain was also claiming a victory in persuading the G20 to reject her attempts to put support for some protectionist measures in the communique. The day before, in a speech to business leaders, Cameron had accused the Argentinians of busting a series of anti-protectionist laws in Kirchner's efforts to shore up her country's economy, and take control of the Falklands.
Hector Timerman, the Argentinian foreign minister, responded to the row saying "Nation states have the obligation to talk. We prepared an envelope containing various papers but the prime minister refused to receive it. Britain continues to refuse to talk and what surprised me most was that David Cameron did not go to the decolonisation meeting on Thursday."
Sensing a diplomatic opportunity, the Argentinians then called a press conference at the G20 summit to detail the crisis.
At a chaotic press conference, the Argentine foreign minister, Héctor Timerman, accused Britain of being a colonial power. "The UK is the most famous colonialist in the world, not Argentina," he said.
The UK needed to respect the UN resolutions, he said. "They cannot demand to other countries to respect their resolutions when they do not do so," he said.
When asked by the BBC if Mrs Kirchner had used the G20 summit to revive the Falklands issue, he replied: "You lie."
At a press conference later, Cameron said it had been an important conversation to have with Kirchner and denied it had been a media stunt by him. He said: "All the countries locked in this dispute say they believe in democracy, human rights and self determination." He said the aim of the Falklands referendum was "to put the issue beyond doubt".
• This article was amended on 20 June 2012. The original wrongly stated that children from the Falklands Islands tried to give Kirchner a letter setting out their love of their homeland as she attended a UN conference in New York. They were a group of young people seeking to invite the Argentinian president to a meeting to discuss mutual issues. This has been corrected.