LOS ANGELES (AP) — A gay Los Angeles couple is suing the U.S. State Department for not recognizing one of their twin sons as a citizen.

Andrew and Elad Dvash-Banks filed the discrimination suit Monday in Los Angeles federal court.

The couple says the U.S. government has failed to recognize their Canadian marriage and one of the 1-year-old fraternal twins born there. Each boy was conceived with sperm from a different father and born by the same surrogate mother minutes apart.

The State Department only granted citizenship to Aiden, who DNA tests showed was the biological son of Andrew, a U.S. citizen. The other son, Ethan, who was conceived from Elad's sperm, was denied citizenship. Elad Dvash-Banks is an Israeli citizen.

The State Department said it doesn't comment on pending litigation.