WASHINGTON—President Donald Trump is pushing changes in immigration laws to make it easier to jail and quickly deport children who cross the border illegally. He also wants to make it harder to pursue asylum.

To him, these are legal “loopholes” that Congress needs to close to stop illegal immigration. But these proposals are even harder to enact than his controversial border wall, in the face of widespread Democratic and some Republican opposition.

“The current immigration and border crisis…are the exclusive product of loopholes in federal immigration law that Democrats refuse to close,” Stephen Miller, the president’s top adviser on immigration policy, told reporters this week.

The Obama administration voiced concerns with some of the same provisions. But for some lawmakers in Congress, they are viewed as critical humanitarian protections for vulnerable children and asylum seekers.

“These are not loopholes,” Sen. Dianne Feinstein (D., Calif.) said at a recent Senate hearing. “They are laws that Congress passed to address the documented injustices facing children in our immigration system.”