Ecuador granted political asylum to WikiLeaks founder Julian Assange on Thursday, setting up a diplomatic confrontation with Britain, which plans to extradite him to Sweden.

Ecuadoran Foreign Minister Ricardo Patino argued the Australian activist would not get a fair trial if he is eventually sent to the United States to be tried for publishing a trove of classified documents.

"The Ecuador government, loyal to its tradition to protect those who seek refuge with us at our diplomatic missions, has decided to grant diplomatic asylum to Mr Assange," Patino said at a news conference.