The Supreme Court agreed on Friday to decide the legality of U.S. President Donald Trump's directive to restrict birthright citizenship in the United States, a contentious part of his efforts to curb immigration and a step that would alter how a 19th-century constitutional provision has long been understood.

The justices took up a Justice Department appeal of a lower court's ruling that blocked Trump's executive order telling U.S. agencies not to recognize the citizenship of children born in the U.S. if neither parent is an American citizen nor a legal permanent resident, also called a "green card" holder.

The lower court ruled that Trump's policy violated the U.S. Constitution's 14th Amendment and a federal law codifying birthright citizenship rights in a class-action lawsuit by parents and children whose citizenship is threatened by the directive.

The justices are expected to hear arguments during their current term and issue a ruling by the end of June. They did not set a date for the arguments.

The Republican president signed the order on his first day back in office on January 20 as part of a suite of initiatives he has pursued during his second term as president to crack down on legal and illegal immigration. Trump's policies towards immigration have been among the most contentious aspects of both his terms as president, with critics accusing him of racial and religious discrimination in his approach.

The 14th Amendment has long been interpreted as guaranteeing citizenship for babies born in the United States. But the Trump administration has argued that the provision does not grant citizenship to the babies of immigrants who are in the country illegally or whose presence is lawful but temporary, such as university students or those on work visas.

"This case will have enormous consequences for the security of all Americans, and the sanctity of American citizenship. The Trump administration looks forward to making its case on the issue of birthright citizenship on behalf of the American people," White House spokesperson Abigail Jackson said.

"No president can change the 14th Amendment's fundamental promise of citizenship," said Cecillia Wang, national legal director of the American Civil Liberties Union, which is representing the plaintiffs. "We look forward to putting this issue to rest once and for all in the Supreme Court this term."

The administration has said that granting citizenship to virtually anyone born on U.S. soil has created incentives for illegal immigration and led to "birth tourism," by which foreigners travel to the United States to give birth and secure citizenship for their children.

The legal challenges appealed by the Justice Department concerned one lawsuit filed by the states of Washington, Arizona, Illinois and Oregon, and another filed in federal court in New Hampshire by plaintiffs who sued on behalf of a nationwide class of people affected by Trump's order.