Hashim Thaci's comments came after a closed-door meeting with the EU foreign policy chief Federica Mogherini, on the sidelines of a Berlin summit called by Germany and France aimed at restarting long-stalled talks between the former wartime foes.
Kosovo declared independence from Serbia in 2008 after fighting a 1998-99 war that ended with NATO intervening to stop a bloody Serbian crackdown of Kosovo Albanian separatists. Serbia does not recognize Kosovo's independence, but the two have been told they must improve bilateral relations to join the EU. The bloc has mediated negotiations aimed at resolving the long-standing Balkan dispute since 2011.
Although Serbian President Aleksandar Vucic formally seeks EU membership, he has gradually drifted Serbia toward Russia. He last week met Russian President Vladimir Putin during a summit in China and said that Russia supports Serbia in the defense of its interests in Kosovo.
The Berlin meeting, which also included leaders from other states in the region, was also expected to touch upon the controversial suggestion of a land swap between the two countries, largely along ethnic lines — something many in the EU hope to prevent.
Although never made official, Vucic and Thaci are thought to be seeking changes, or "corrections," to Kosovo's borders as part of an overall agreement. On the sidelines of the meetings, Vucic told reporters "we are against border changes but are ready to talk about all possible solutions."
Heading in, Chancellor Angela Merkel and French President Emmanuel Macron tamped down expectations of concrete results, saying it was more about providing an open forum for regional leaders to discuss issues.
"It is a step on a very long road, and not necessarily a results-oriented process today," Merkel told reporters. Macron added that it was in Europe's wider interest to foster stability in the region. "We have no intention of prescribing a solution," Macron said. He added that leaders want to "look at all possible options, take the heat out of the debate and advance without taboos and without giving rise to new regional tensions."
He said France had been deeply engaged in the Balkans in the past and announced a new "policy of re-engagement in the region" including more work on economic and social development, security and defense, and justice issues, but didn't provide details.
After his meeting with Mogherini, Thaci told reporters there was "no prospect of any agreement between Kosovo and Serbia" at the Berlin meeting. "No talks or agreement are possible without the participation of the United States of America," he told reporters. "The European Union's is too weak and disunited to move things forward in the Western Balkans," before walking over to the U.S. Embassy in Berlin for meetings with U.S. President Donald Trump's top diplomat in Germany, Ambassador Richard Grenell.
Mogherini raised Kosovo's ire in December when she called on Kosovo to lift tariffs on goods from Serbia to defuse a standoff between the two countries. Serbia has said it will not resume talks until the tariffs are revoked, and Vucic said after his own meeting with Mogherini that he was prepared to resume talks once they are.
The 100 percent tariff on goods imported from Serbia was set in November. Prime Minister Ramush Haradinaj has said the tariff will only be lifted when Belgrade recognizes Kosovo's sovereignty and stops preventing it from joining international organizations.
Last month, a high-ranking U.S. envoy urged Serbia and Kosovo to stop provoking one another and resume the European Union-mediated talks on how to normalize relations, while also calling Kosovo to drop or suspend the 100 percent tariff on Serbian goods.
With Kosovo pushing for more involvement from Washington, there has been speculation that Serbia may respond by asking for Moscow's participation.
Associated Press writers Llazar Semini in Tirana, Albania, Dusan Stojanovic in Belgrade, Serbia, and Elaine Ganley in Pariscontributed to this report.