A senior U.S. official has met with Kosovo top leaders trying to convince Pristina to revoke or suspend a tariff on Serb goods so that dialogue with Serbia can resume.

Under Secretary of State for Political Affairs David Hale is the latest U.S. envoy to take part in shuttle diplomacy between Pristina and Belgrade. He met on Saturday with Kosovo's president, speaker and prime minister. A day earlier, he was in Belgrade.

Kosovo Prime Minister Ramush Haradinaj has resisted U.S. calls to suspend the tariff, saying it will only be lifted when Belgrade recognizes Kosovo's sovereignty and stops preventing it from joining international organizations.

Serbia says it will not take part in the European Union-facilitated discussions until the 100-percent tax is lifted.

Serbia doesn't accept Kosovo's 2008 declaration of independence.