Ecuador on Monday responded to the UK government over its statements on the languishing legal case of WikiLeaks founder Julian Assange, who has been living in asylum at the Ecuadorian embassy in London for more than three years.

Last week, the UK's Foreign Office lodged a formal protest against Ecuador for blocking Assange's case from moving forward, claiming that giving him asylum prevents Britain from extraditing Assange to Sweden, where he is wanted for questioning over sexual assault allegations. The Foreign Office called his extradition a legal obligation.

Ecuador's acting Foreign Minister Xavier Lasso rejected those claims. "It is not acceptable to try to place the responsibility for the lack of progress in this area over the last five years on Ecuador," he said Monday. "The republic of Ecuador will not take lessons from any foreign government, least of all those that are unaware of the institution of political asylum, its legitimacy, attached and enshrined in international law, and its humanitarian nature based on the sovereign equality of nations."

The British government had previously threatened to "violate the immunity of diplomatic premises" and has kept a police cordon outside the embassy around the clock at a sky-high cost to taxpayers, Lasso said. "The British government has the sole responsibility for such an invasive and unnecessary police deployment."

Three of the four investigations pending against Assange were dropped last week after the ability to bring charges expired. The WikiLeaks founder has repeatedly invited Swedish prosecutors to interview him at the embassy, but they have rejected those requests. Assange has said he fears that submission to Swedish authorities will lead to his extradition to the U.S. due to his work exposing classified Pentagon and State Department documents.