BERLIN (Reuters) - Germany’s foreign minister Sigmar Gabriel said on Wednesday that Balkan countries must implement reforms and work to overcome age-old divisions if they want to join the European Union.

German Foreign Minister Sigmar Gabriel speaks during a news conference with his Greek counterpart Nikos Kotzias (not pictured) following their meeting at the ministry in Athens, Greece, March 23, 2017. REUTERS/Alkis Konstantinidis

He was due to meet leaders in Serbia and Kosovo this week on his first visit to the region as foreign minister. Next week, the former economy minister visits Albania.

“I will assure my discussion partners: ‘The path toward the EU remains open if you choose reforms and progress instead of division and stagnation,’” Gabriel said in a statement.

The wounds of the past were still fuelling tensions in the region, he said, noting that there had also been remarkable progress in the Western Balkans in recent years.

“We want to support the countries in the region in the development of democracy and the rule of law, and as they move toward stability and prosperity,” Gabriel said.

Last month, Serbian Prime Minister Aleksandar Vucic warned German Chancellor Angela Merkel of serious consequences, including growing nationalism and pro-Russian sympathies, if the EU does not give Western Balkan states a clear message on membership.

Vucic said Britain’s vote to leave the EU, tensions between EU members and Greece’s continued economic struggles had unsettled many in the Balkans, fanning concern about future prospects for joining the bloc.

Gabriel is due to meet with Vucic and Serbian Foreign Minister Ivica Dacic on Wednesday before traveling on to Kosovo, where he will meet Kosovan Prime Minister Isa Mustafa and Foreign Minister Enver Hoxhaj.

His visit comes after thousands of protesters rallied for days to protest against Vucic’s victory in an April 2 presidential election, many chanting “End the dictatorship”.

Protesters see Vucic as an autocrat and his Serbian Progressive Party as corrupt. Vucic has vowed to maintain a balancing act between the West and Russia, its traditional Orthodox Christian and Slavic ally.

U.S. Navy Admiral Michelle Howard told Reuters on Saturday that she hoped tensions between Serbia and Kosovo would calm down after a series of “engineered provocations” in recent months ahead of the Serbian election.