Argentina's president said her nation still has sovereign right to the Falkland Islands, which have been under British control since the 19th Century, according to UPI. President Cristina Fernandez and her administration have been increasing the pressure on Britain to negotiate a stake in the Falklands, after the recent discovery of oil increased the value of the sparsely populated island chain. Fernandez herself has expressed frustration with British Prime Minister David Cameron, and the industry minister has urged reductions in imports from the U.K, the Washington Post said. Foreign Minister Hector Timerman has warned that oil companies operating in the Falklands were doing so illegally and could face stiff fines levied by Argentina. The Post said the residents of the Falklands remain steadfast in wanting to remain under British control, and Cameron has been doing his best to honor their wishes. British diplomats have been visiting various Latin American capitals to explain their side of the dispute, and a Royal Navy destroyer was dispatched to the area to reinforce the troops stationed there. "The absolutely vital point is that we are clear that the future of the Falkland Islands is a matter for the people themselves," Cameron told Parliament earlier this year. "And as long as they want to remain part of the United Kingdom and be British, they should be able to do so."