Updated

A senior United States official is urging Macedonia and Greece to seize the moment to resolve a decades-long dispute over the Balkan country's name that has prevented it from joining NATO.

Assistant Secretary of State for European and Eurasian Affairs Wess Mitchel visited Macedonia's capital, Skopje, on Tuesday as part of a Balkan tour. He told media "there is a tremendous opportunity" for Skopje and Athens to reach a deal over the long-running spat.

Macedonia and Greece have been at odds for a quarter-century over the name Macedonia, but have pledged to resolve the dispute by the summer. Greece argues the country's name harbors territorial claims on its own northern province of Macedonia.

The two countries have intensified talks recently in hopes of finding a compromise to end the dispute.