VIENNA, Austria — A 25-nation group supervising Kosovo’s democratic progress announced Monday that it will end oversight of Europe’s youngest independent nation in September, a move that will bring the ethnically divided country closer to its aspirations of European Union and NATO membership.

The decision, announced Monday in Vienna by Pieter Feith of Kosovo’s International Civilian Office, reflected confidence that Kosovo’s leadership could reduce tensions between majority ethnic Albanians and minority Serbs. However, international military and police units will still patrol Kosovo to lower the risk of ethnic violence.

Such violence still occurs, even 13 years after a NATO bombing campaign ended war between the two sides and the former Serbian province was put under international control. Kosovo Prime Minister Hashim Thaci —a former ethnic Albanian guerrilla commander — pledged to work hard for reconciliation.

“I will communicate and co-operate with every single Serb leader elected in the North who respects the institutions of Kosovo,” he told reporters in Vienna, referring to the country’s restive northern Serb enclave, which has been at the forefront of defying his government’s authority.

Feith said “much remains to be done” in Kosovo’s transformation into a Western-style democracy that meets EU criteria. But he also noted progress, including in the northern Serb region whose people had long seen neighbouring Serbia as their lifeline but now in “increasing numbers are asking for services from the Kosovo government. ”