BELGRADE, Serbia (AP) — Serbia's leader is urging U.S. President Donald Trump to put pressure on Kosovo to return to negotiations amid a months-long deadlock.

EU-mediated status talks between Serbia and its ex-province have been stalled since late last year when Kosovo imposed a 100% tax on goods imported from Serbia.

Kosovo declared independence in 2008 which is recognized by the U.S. and most of the West, but not by Serbia and its allies Russia and China.

Serbian President Aleksandar Vucic said in a letter Friday congratulating Trump on his birthday that he has been following the U.S. president's "energetic" and "brave" work that sometimes leads to "an unexpected approach to resolving problems."

Vucic says he's asking Trump to influence Pristina to lift the taxes so talks on finding "a compromise" solution can resume.