WASHINGTON (AP) — President Donald Trump has signed a $4.6 billion aid package to help the federal government cope with the surge of Central American immigrants at the U.S.-Mexico border.

Many Democratic lawmakers were hoping for more. They wanted stronger protections for how migrants are treated at holding facilities and to make it easier for lawmakers to make snap visits.

The White House had threated to veto the legislation on grounds that it would hamstring border security efforts. Democratic House Speaker Nancy Pelosi was forced to accept the Republican-controlled Senate’s version of the aid package, frustrating the more liberal members of her caucus.

The bill bolsters care for tens of thousands of arrivals taken into custody monthly and sets guidelines for how the Trump administration must handle them.