Indonesia has condemned the Oxford City Council for its recognition of West Papuan independence leader Benny Wenda.
Mr Wenda was given the Honorary Freedom of the City during a ceremony at the Oxford Town Hall on Wednesday.
The chairman of the United Liberation Movement for West Papua was granted political asylum in the UK in 2002.
But in a statement, Indonesia's Foreign Ministry criticised giving the award to Mr Wenda, who it described as a "separatist activist."
The statement said Oxford City Council had failed to understand development and improvement in Papua.
"Indonesia will still be strongly against separatism and will not back down in fighting for the Unitary State of the Republic of Indonesia."
Mr Wenda settled in Oxford after reading resident and British writer George Monbiot's investigative book on human rights abuses in West Papua, Poisoned Arrows. Mr Monbiot attended the award ceremony on Wednesday, along with several British MPs.
In May, a group of MPs urged the government to do more to press Indonesia to stop human rights abuses and violence in Papua during a debate in the House of Commons.