The European Court of Justice on Tuesday opened a hearing on the recognition of same-sex marriages in European Union countries where they aren't legal.

The hearing in Luxembourg came after Romania's constitutional court asked the European court to make a ruling on the issue amid a court case in Romania brought by a Romanian-American couple who want their 2010 union to be recognized. Same-sex marriage isn't legally recognized in EU member Romania.

Iustina Ionescu, a Romanian lawyer, told the court the couple's marriage should be recognized based on the EU principle of free movement.

"We have confidence in the wisdom of the European judges that they will have the capacity to take a decision in our favor which corrects the injustices in Romania," said Adrian Coman, who has been fighting since 2012 to get his marriage to U.S. citizen Claibourn Robert Hamilton legally recognized in the same way it would be if they were a heterosexual couple.

However, representatives from Romania, Hungary, Poland and Estonia told the court Tuesday they don't want the term "spouse" to include same-sex unions.

European Commission officials said that same-sex marriages or civil partnerships are recognized or enjoy legal protection in 22 out of EU's 28 members.