Indonesia Monday summoned the British ambassador to make a protest after a group supporting independence for the restive Papua region set up its headquarters in England, the envoy said.
Mark Canning said he was summoned to see Foreign Minister Marty Natalegawa, who "conveyed to me in clear terms the strong concern of the Indonesian government at the opening of a 'Free West Papua' office in Oxford".
The "Free West Papua" group last month established the headquarters in the central English city, and the opening ceremony was attended by the mayor and a member of parliament.
"I explained to the minister that we recognised the sensitivity of this issue for Indonesia," said Canning in a statement.
"The position of (the) British government on this matter is quite clear. We respect the territorial integrity of Indonesia and do not support calls for Papuan independence. We regard Papua as being part of Indonesia."
After their meeting, Natalegawa said that "we cannot accept and we object to the opening of the office".
He said Canning had stressed that the views of local authorities in Oxford "do not represent the view of the British government and this is not something that is in line with the position of the British government".
The issue of separatism in Indonesia remains deeply sensitive, particularly after the bloody secession of East Timor which gained independence in 2002.
For decades, ethnic Papuans in the mountainous and sparsely populated region have rejected the area's special autonomy within Indonesia.
They have demanded a referendum on self-determination for the region's estimated population of 3.6 million.
The vast area is split into two provinces for administrative purposes, Papua and West Papua. But some -- such as the group which set up the office in Oxford -- refer to the whole region as West Papua.
Indonesia has strict treason laws and courts have handed down stiff penalties ranging from 20 years' jail to life for people caught with separatist symbols such as the Papuan flag.
Around 130 people are currently imprisoned in Indonesia for peacefully promoting separatism, most of them from Papua or the eastern Maluku islands, according to Human Rights Watch.