US President Donald Trump's national security advisor on Friday said Washington does not "exclude" the possibility of territorial adjustments in the dispute between Serbia and Kosovo, a notion Western powers have staunchly opposed in the past.
"If the two parties can work it out between themselves and reach agreement -- we don't exclude territorial adjustments," John Bolton said during a press conference in Ukraine's capital Kiev.
"And I do not think anybody in Europe would stand in the way if the two parties reach the mutually satisfactory settlement," he said. "I think they both can be congratulated for the early tentative discussions that they had."
Bolton's comments signal a shift in the US position on border changes in the fragile region still haunted by the bloody break-up of Yugoslavia.
The leaders of Serbia and Kosovo are in EU-brokered talks to overcome a bitter diplomatic stalemate that has thwarted both governments' aspirations to join the bloc.
At the heart of the "frozen conflict" is Belgrade's refusal to recognise Kosovo -- an ethnic Albanian majority province that broke away from Serbia after a bloody guerilla conflict in the late 1990s, declaring independence in 2008.
Another sticking point is Belgrade's desire to keep strong links with the Serb minority in northern Kosovo.
Recent talk by both parties about possible border adjustments raised fears of potential conflict in the region still simmering with ethnic tensions, with both Germany and the UK warning that such rhetoric can lead to instability.