The Argentine charge d'affaires was summoned to the Foreign Office this afternoon.
A Foreign Office spokesman said: "We have raised our concerns with the Argentine charge in London this afternoon, who will report back to Buenos Aires for urgent clarification.
"We made clear that such actions against legitimate commercial activity were a matter of concern not just for the UK, but for the EU as a whole, and that we expect the EU to lodge similar concerns with Argentine authorities."
It comes after Downing Street accused Argentina of pursuing a "policy of confrontation" over the Falkland Islands, after reports suggested the South American state's government was calling on companies to stop importing goods from the UK.
Prime Minister David Cameron's official spokesman said that the Argentine move was "counter-productive" and amounted to a misreading of British resolve over the disputed islands. The Foreign Office is raising the issue with the Argentine embassy.
Argentine state news agency Telam today reported that industry minister Debora Giorgi has called on the country's top companies to replace imports from the UK with goods produced elsewhere.
Her initiative marks the latest escalation of the confrontation over the islands as the 30th anniversary of the Falklands War approaches.
Buenos Aires has complained to the United Nations of British "militarisation" of the south Atlantic, following the deployment of a new Royal Navy warship to the Falklands, as well as the Duke of Cambridge's tour of duty as an air-sea rescue pilot on the islands.
And on Monday, two cruise ships were turned back from the Argentine port of Ushuaia, apparently because they had visited the Falklands.
Asked about the reported plan to block British imports, Mr Cameron's spokesman told reporters at a regular media briefing in Westminster: "It is clearly very sad that Argentina continues with their policy of confrontation instead of co-operation.
"We think that is counter-productive and also a complete misreading of Britain's resolve on this issue.
"The UK is also a major investor in Argentina and we import goods from Argentina. It is not in Argentina's economic interest to put up barriers of this sort.
"The right approach here is one of co-operation, not confrontation."