LOS ANGELES -- Ethan and Aiden Dvash-Banks are toddler twins who share almost everything: the same toys, the same nursery, the same clothes and the same parents. Everything but a toothbrush and U.S. citizenship.

To remedy what their parents, a gay married couple, view as an injustice, Ethan Dvash-Banks became a plaintiff at the tender age of 16 months in a federal lawsuit against the U.S. State Department that seeks the same rights his brother has as an American citizen.

Each boy was conceived with donor eggs and the sperm from a different father - one an American, the other an Israeli citizen - but born by the same surrogate mother minutes apart.

"What we're trying to do is pursue justice for Ethan," said Elad Dvash-Banks, Ethan's biological dad, "and correct a wrong that the State Department is continuing to pursue that might affect other couples."

The lawsuit was one of two filed Monday by an LGBTQ immigrant rights group that said the State Department is discriminating against same-sex binational couples by denying their children citizenship at birth. The cases filed in Los Angeles and Washington by Immigration Equality said the children of a U.S. citizen who marries abroad are entitled to U.S. citizenship at birth no matter where they are born and even if the other parent is a foreigner.

The State Department said it doesn't comment on pending litigation, but pointed to guidance on its website that says there must be a biological connection to a U.S. citizen to become a citizen at birth.

Aaron Morris, executive director of Immigration Equality, said the State Department is wrongly applying a policy for children born out of wedlock to married same-sex couples.

"If a mother and father walk into a consulate and have a marriage certificate and birth certificate, they're never asked any questions about the biology of the child," said Aaron Morris, executive director of Immigration Equality. "But the converse is also true and every same-sex couple will be asked that."

The other case filed Monday involves two women, one from the U.S., and one from Italy, who met in New York, wed in London and each gave birth to a son. The State Department didn't recognize the couple's marriage, the lawsuit said, and only granted citizenship to the boy whose biological mother was born and raised in the U.S.

Citizenship issues frequently arise with births overseas -- even for heterosexual U.S. citizens -- and particularly with the use of artificial insemination and surrogates, said immigration lawyer Ally Bolour, who is not involved in the lawsuit. The Supreme Court's rejection in 2013 of the Defence of Marriage Act (DOMA), which had barred the federal government from recognizing same-sex marriages, opened the door to the potentially ground-breaking challenges now being brought, he said.

"This is an absolutely fascinating, cutting edge area of law that stems from (DOMA) being overturned," Bolour said. "It was just a matter of time for this issue to be decided by the courts."

Andrew Dvash-Banks was studying in Israel when he met his future husband, Elad, an Israeli citizen. Because they couldn't marry at the time in the U.S. or in Israel, they moved to Canada, where they wed in 2010. The children were born by a surrogate in September 2016.

Everything seemed fine until the couple brought their cranky infants to the American consulate in Toronto a few months later to apply for citizenship and the woman at the counter began asking probing questions they found shocking and humiliating.

The consular official told them she had discretion to require a DNA test to show who the biological father was of each boy and without those tests neither son would get citizenship. The men knew that Andrew was Aiden's biological father and Elad was Ethan's but they had kept it a secret and hadn't planned on telling anyone.

"I started crying," Andrew Dvash-Banks said. "These are twins, how can you differentiate between them? They were born minutes apart."

After submitting the DNA test results that proved who fathered each boy, the couple received a large and small envelope from the U.S. on March 2. The big one included Aiden's passport. The other was a letter notifying Andrew that Ethan's application had been denied.

The family has since moved to Los Angeles to be closer to Andrew Dvash-Banks' family. Ethan came on a tourist visa that expired last month.

"He doesn't have legal status," Andrew Dvash-Banks said.