EU commissioner goes against Merkel on Balkans borders

"We should leave it to them [Serbia and Kosovo] ... finding a solution will be supported by us if the overall setting is OK," he added.

"It's about a bilateral solution which should not serve as a blueprint for other issues," he also said.

Hahn spoke to media alongside Serbian president Aleksandar Vucic and his Kosovar counterpart Hashim Thaci.

Both men have, in recent months, begun openly discussing the idea of a new territorial accord.

The changes would likely involve giving the Presevo Valley, an ethnic Albanian area in southern Serbia, to Kosovo in return for handing ethnic Serb areas in northern Kosovo to Serbia.

A deal could help normalise relations 20 years after the war ended, paving the way for EU accession down the line.

But it could stir instability in the Western Balkans if other minorities, such as Croats and Serbs in Bosnia or Albanians in Macedonia, also tried to change borders for the sake of ethnic purity.

"We want to reassure our neighbour countries, EU member states, and other countries in the world, not to be afraid of a potential peaceful agreement between Kosovo and Serbia, even if such a deal implies a border correction," Kosovo's Thaci said on Saturday.

"We are not problematic guys - we are trying to do an agreement," he said.

Serbia's Vucic described the status quo as a "frozen conflict."

"Someone one day will de-freeze it and then we'd have a war. And none of us wants a war," he said in Alpbach.

Merkel's law

The EU commissioner's comments flew in the face of the German and UK position on the issue.

"The territorial integrity of the states of the Western Balkans has been established and is inviolable," German leader Angela Merkel said in Berlin on 13 August after meeting Bosnian president Denis Zvizdic.

"This has to be said again and again because again and again there are attempts to perhaps talk about borders and we can't do that," she said.

The UK ambassador to Kosovo, Ruairi O'Connell, told Kosovo's T7 broadcaster on 15 August that "borders are written in words, but they change with bullets".

The US and the EU have in the past walked in lockstep on Western Balkans policy after Nato intervention helped to end the 1990s wars there.

US switch

But the White House went against Merkel on Friday, when John Bolton, US president Donald Trump's national security advisor, also backed a potential border change.

"If the two parties can work it out between themselves and reach agreement, we don't exclude territorial adjustments," Bolton said while in Kiev on 24 August.

"We wouldn't stand in the way, and I don't think anybody in Europe would stand in the way, if the two parties to the dispute reached a mutually satisfactory settlement," he said.

With Russia and China opposed to Balkans border changes, the EU commission's Hahn said in Alpbach that EU states had a "responsibility" to play a leading role in conflict resolution.

"It's our task, our responsibility to care about European countries and not to leave it to other parties, third parties somewhere in the world," Hahn said.