The Falkland Islands will be back under Argentine control within "20 years", the country's foreign minister Hector Timerman has said.
On a visit to London, he claimed "not one" other nation supported UK sovereignty of the Falklands.
A referendum on the Falkland Islands political status will be held in March.
Mr Timerman was meanwhile confronted by elected representatives of the Falkland Islands in the House of Commons Lobby on Tuesday.
The foreign minister refused to accept a letter about the future of the Islands or to talk to the representatives.
He was in the Commons to address the All Party Group on Argentina.
Mr Timerman, who spoke to reporters at the Argentine embassy in London, said the UK "never missed an opportunity to miss an opportunity to find a solution for the Malvinas", the Argentine name for the islands.
Relations between the British and Argentine government have soured in recent months. Last year marked 30 years since the Falklands War, when the islands were occupied by Argentine forces for 74 days.
On the subject of re-gaining sovereignty, Mr Timerman said: "I don't think it will take another 20 years. I think that the world is going through a process of understanding more and more that this is a colonial issue, an issue of colonialism, and that the people living there were transferred to the islands.
"We have been trying to find a peaceful solution for 180 years. I think the fanatics are not in Buenos Aires [but] maybe in the United Kingdom because they are 14,000km (8,700 miles) away from the islands.
"I think they are using the people living in the islands for political [reasons] and to have access to oil and natural resources which belong to the Argentine people. I think we are not fanatical at all," he insisted
Mr Timerman rejected an invitation to discuss the issue with Foreign Secretary William Hague last week, after Mr Hague invited members of the Falkland Islands government to the meeting.
"According to the United Nations, there are only two parties to the conflict - the United Kingdom and the Republic of Argentina. It is an issue that has to be resolved by Argentina and the United Kingdom.
"By introducing a third party [the Falklanders], the United Kingdom is changing more than 40 resolutions by the United Nations, which call the two countries to negotiate."
'Face to face'
The Argentine ruled out a "military solution" to the dispute, but claimed "not one single country in the world" supports the British right to sovereignty over the Falklands.
He refused to discuss whether Argentina would be prepared to thrash out a joint-sovereignty agreement or propose such a solution, saying: "When we sit down we will discuss everything that has to be discussed, not before. You don't discuss through the media. You discuss face to face.
"That is why I ask for a meeting with William Hague and he refused. If I can sit down with him, he will know what we think, but he refuses to sit down with us."
He also dismissed the forthcoming referendum - on whether the Islanders want to remain part of the British Overseas Territories - as meaningless.
"If you ask the colonial people who came with a colonial power and replaced the people who were living in the islands, it is like asking the British citizens of the Malvinas Islands if they want to remain British," he said.