A gay Romanian-American couple should enjoy the same residency rights as other married couples in the European Union, a top EU legal adviser said in an opinion published Thursday.

European Court of Justice Advocate General Melchior Wathelet said the key legal issue in the case of Romanian Adrian Coman and his American husband, Claibourn Robert Hamilton, was "not that of legalization of marriage between persons of the same sex but that of freedom of movement of a Union citizen."

So while the 28 European Union countries "are free to provide or not for marriage for persons of the same sex," they must not limit their application of spousal rights in a way that infringes "on the right of citizens of the Union and their family members to move and reside freely within the territory of the Member States," Wathelet wrote.

Coman has been fighting since 2012 to get his marriage to Hamilton in Belgium two years earlier recognized in Romania, which does acknowledge same-sex unions. The couple live in New York.

Romania's Constitutional Court asked the European Court of Justice to weigh in with its legal interpretation of the case. Thursday's decision is non-binding, but the court often follows the recommendations laid out by its advocates general.

"We are overjoyed," Hamilton said in a written statement. "It shows the Romanian authorities were wrong to refuse to treat us as a family."

Coman added: "Romanian citizens can't be divided into good and gay. We can't be treated as inferior citizens, lacking equal rights, based on prejudices that some have about homosexuality."

The court is expected to make a final ruling this year.