A State Department spokesman Richard Boucher Monday said Sunday's referendum reaffirms the strong desire of Macedonians to continue progress towards NATO and European Union membership.
The measure sought to overturn a law that redrew municipal boundaries and gave ethnic Albanians more influence in areas where they are at least 20 percent of the population.
The referendum failed when turnout was less than the required 50 percent of eligible voters.
The spokesman said last week's U.S. recognition of the Balkan country as the Republic of Macedonia showed America's commitment to a peaceful and democratic Macedonia. Greece protested the move. It has a province called Macedonia and considers the use of the name a threat to its territorial integrity.