The proposal is almost certainly illegal, experts said, but President Trump’s eagerness to entertain it showed his willingness to embrace extreme measures to demonstrate he is tough on crime.

SAN JOSE, Costa Rica (AP) — Secretary of State Marco Rubio said Tuesday that El Salvador’s offer to accept and jail violent American criminals raises clear legal issues but described it as “very generous” and said that President Donald Trump would make a decision on whether to accept it.

El Salvador has agreed to accept criminal illegal immigrants of any nationality as the United States works to deport hundreds of Venezuelan Tren de Aragua gang members. The agreement, announced by Salvadoran President Nayib Bukele‘s administration late Monday,