The Trump administration earlier this year reportedly considered detaining migrant children at Guantánamo Bay, the 17-year-old U.S. prison in Cuba that human rights advocates have condemned as a horrific stain on American history.

“The idea of incarcerating children at Guantánamo should send chills down the spine of anyone with a conscience,” Sen. Jeff Merkley (D-Ore.) tweeted Tuesday. “This is what happens when our president is so racist that he sees migrant children as an ‘invasion’ and not vulnerable children to be protected.”

The Trump administration’s proposal was first reported by the New York Times, which explained that Guantánamo “has a dormitory facility that has been used in the past to hold asylum-seekers.”

Officials with the Department of Homeland Security “examined” the plan earlier this year, the Times reported.

According to the Times:

While there were no ‘immediate’ plans to house migrant children at Guantánamo Bay, the Defense Department is attempting to identify military bases that might be used for that purpose, a department spokesman, Tom Crosson, said on Monday… Meanwhile, authorities are struggling to identify new locations where migrants can be held in detention. The military awarded a $23 million contract in February to build a ‘contingency mass migration complex’ at Guantánamo, a plan that would expand the existing facility to house 13,000 migrants and 5,000 support staff in tents. That project appears intended primarily to accommodate a crush of migrants that might accompany a new crisis in the Caribbean, though it could theoretically be used to house Central Americans.

Physicians for Human Rights, an advocacy group that has long called for the closure of Guantánamo, called the Trump administration’s proposal “beyond appalling.”

Beyond appalling: “In one initiative examined earlier this year, Department of Homeland Security officials looked at housing #migrant #children at #Guantánamo Bay, Cuba, which has a dormitory facility that has been used in the past to hold asylum seekers.” https://t.co/9qfPh77vYg — Physicians for Human Rights (@P4HR) April 23, 2019

The human rights group Amnesty International also denounced the reported plan on Twitter.

“Kids should not be in detention, period. And even considering putting them Guantánamo Bay is inhumane,” the organization said Tuesday. “Detaining asylum-seekers is a choice, and it’s a harmful and irresponsible one. The Trump administration’s mass detentions must come to an end.”