WASHINGTON: US President Donald Trump's effort to curtail automatic birthright citizenship as part of his immigration crackdown suffered a further setback as a third federal judge said on Monday he would block it.

At the urging of immigrants rights groups represented by the American Civil Liberties Union, U.S. District Judge Joseph Laplante in Concord, New Hampshire, said he would issue a preliminary injunction blocking implementation of the executive order Trump signed upon his return to office on Jan. 20.

The Republican president's order directed U.S. agencies to refuse to recognize the citizenship of children born in the United States after February 19 if neither their mother nor father is a U.S. citizen or lawful permanent resident.

Laplante, an appointee of Republican former President George W. Bush, said during a court hearing that he would explain his reasoning in a forthcoming written decision that he expected to be appealed and to not be the last word on the topic.

"This issue is going to be resolved one way or another by the Supreme Court," Laplante said.

The preliminary injunction he issued created an extra legal barrier preventing Trump's order from taking effect, after federal judges in Maryland and Washington state last week issued separate injunctions blocking the order's enforcement nationwide.

Any appeals the Trump administration pursues could now wind through three different federal appeals courts, including the Boston-based 1st U.S. Circuit Court of Appeals, whose only active judges are Democratic appointees and which has jurisdiction over New Hampshire.

The U.S. Department of Justice did not immediately respond to a request for comment.

The case before Laplante was filed by three immigrants rights' organizations, who said they had pregnant members whose babies upon being born would be unconstitutionally denied citizenship under Trump's order.

ACLU attorney Cody Wofsy said the order violated the citizenship clause of the U.S. Constitution's 14th Amendment and a 1898 U.S. Supreme Court ruling, United States v. Wong Kim Ark, interpreting that amendment as recognizing the right to birthright citizenship regardless of a child's parents' immigration status.

"This order is a fundamental attack on the Constitution," Wofsy said.

But Justice Department attorney Drew Ensign said the plaintiffs were relying on non-binding parts of that Supreme Court ruling, which only guaranteed citizenship for children whose parents permanently resided in the county.

"That's a line that's already been drawn by the Supreme Court," he said.