Julian Assange could be kicked out of Ecuador's embassy in London after the country's foreign minister said the situation was "not sustainable."

The WikiLeaks founder was granted asylum in 2012 to avoid extradition to Sweden over rape allegations, and has been holed up in Knightsbridge for five-and-a-half years. 

Swedish prosecutors have dropped their investigation into the allegations, but Mr Assange, who denied the allegations, fears he will be extradited to the United States if he leaves the building and that there is a sealed indictment ordering his arrest.

WikiLeaks published thousands of classified military and diplomatic documents, in one of the largest information leaks in US history.

Maria Fernanda Espinosa, Ecuador's foreign minister, said her country was now seeking possible mediation to resolve the impasse, which she called "not sustainable." 

"We're considering, exploring the possibility of a mediation," she said, adding that a third country or person could lead a potential mediation.

"No solution can be reached without international cooperation and without cooperation from the United Kingdom, which in addition has shown interest in finding a solution."