President Donald Trump said Wednesday his administration is “very seriously” considering ending birthright citizenship via executive order.

“We’re looking at that very seriously. Birthright citizenship, where you have a baby on our land — walk over the border, have a baby, congratulations, the baby’s now a U.S. citizen.

“We’re looking at that very seriously,” Trump told reporters at the White House. “Birthright citizenship, where you have a baby on our land — walk over the border, have a baby, congratulations, the baby’s now a U.S. citizen. We are looking at birthright citizenship very seriously. It’s, frankly, ridiculous.”

Trump said on the campaign trail in 2016 that he wanted to end the practice that grants citizenship to all who are born in the United States, and has made immigration reform one of his signature policies. He also said last year he would sign an executive order to make it happen.

Lawmakers, including a number of Republicans, have pushed back on the idea, arguing that a president lacks the authority to make such a drastic change to the country’s immigration laws. Birthright citizenship was enacted under the 14th Amendment of the Constitution.

However, Trump said he would end birthright citizenship “one way or another.”

During his time in office and on the campaign trail, Trump has railed against immigration, both illegal and legal. His administration enacted a “zero tolerance” policy that led to the separation of thousands of migrant families, drawing both applause and outrage from all corners of the country.

Earlier on Wednesday, the Trump administration said it was proposing a new rule that would allow migrant families to be detained indefinitely, ending the Flores Settlement Agreement that says children cannot be held longer than 20 days.

The new rule would basically end catch and release, and would allow families to be held during their court proceedings. Officials claim the proceedings could be resolved in about three months.

“This rule allows the federal government to enforce immigration laws as passed by Congress,” interim Homeland Security Secretary Kevin McAleenan said via a statement.

Trump also has sought changes to the asylum laws, attempting to keep Central American migrants in Mexico, and last week he introduced a new rule that would make it far more difficult for low-income immigrants who are on food stamps or other forms of taxpayer-funded public assistance to renew their green cards and remain in the country legally.