WASHINGTON — Senior adviser Stephen Miller on Sunday echoed what President Donald Trump told reporters outside the White House on Wednesday: the administration is looking at trying to end the practice of granting citizenship to anyone born in the United States.

Miller, the architect of some of Trump’s hard-line immigration ideas, told Fox News, “we’re looking at all legal options” regarding the practice known as birthright citizenship.

Many legal scholars exclude people in the U.S. on a temporary basis or in the country illegally from a key provision in the 14th Amendment of the U.S. Constitution, Miller said. It reads, “All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States.”

“That’s something that we have to look at,” Miller said.

Miller did not provide a timeline for when he expects to have a “correct” interpretation of the 14th Amendment.

Asked by reporters on Wednesday whether he’d sign an executive order on birthright citizenship, Trump said, “We’re looking at that very seriously.”

“Where you have a baby on our land — you walk over the border, have a baby. Congratulations, the baby is now a U.S. citizen,” Trump said. “We are looking at birthright citizenship very seriously. It’s frankly ridiculous.”