Serbia has informed its former province of Kosovo that Foreign Minister Hashim Thaci will be arrested if he tries to attend a conference in Belgrade this week in what would have been a landmark visit by the former guerrilla commander.

Thaci is invited to a civil society event on regional reconciliation in the Serbian capital on Friday. He had said he hoped to attend.

The prospect put Serbia's government in an awkward spot.

While it has negotiated with Thaci for years in various European capitals, he is wanted by Serbian police for his role in an armed uprising against Serbian repression of Kosovo's ethnic Albanian majority in the late 1990s.

Thaci, sentenced in absentia in 1997 to 10 years in a Serbian jail for terrorism, went on to become prime minister of Kosovo, presiding over the territory's 2008 declaration of independence from Serbia and taking part in European Union-mediated talks aimed at settling relations between the two.

In a letter to the Pristina authorities, seen by Reuters, Dejan Pavicevic, Serbia's liaison officer for Kosovo, said the court's verdict against Thaci was fully in force.

"It is my duty to inform you that Mr. Thaci will accordingly be detained at the first contact with any of the law enforcement agencies of the Republic of Serbia and brought before the competent court of law," Pavicevic said.

Thaci last month shared coffee and a joke with his Serbian counterpart, Ivica Dacic, in Kosovo's capital, underscoring the progress made by the European Union in cooling tensions by offering the potential of integration with the bloc.