Washington (CNN) -- President Barack Obama signed a bill Friday that provides $600 million in emergency funding to help secure the U.S.-Mexico border.

A day earlier, two senators -- Democrats Charles Schumer of New York and Ben Cardin of Maryland -- returned from their August recess to give the chamber's approval for the bill.

The House of Representatives had already approved the measure.

In the Senate, the bill passed by unanimous consent -- a parliamentary term for a voice vote that doesn't require the return of the entire Senate chamber. GOP leaders had agreed to the maneuver.

Among other things, the bill provides for roughly 1,500 new law enforcement agents, new unmanned aerial vehicles, new forwarding operating bases and $14 million in new communications equipment.

The measure has attracted strong Democratic and Republican support.

Obama praised the plan after the Senate passed it, saying that congressional passage "answers my call to bolster the essential work of federal law enforcement officials and improve their ability to partner with state, local and tribal law enforcement."

Obama argued that the new law would facilitate cooperation along the border between the U.S. and Mexican governments, and asserted that it would make "an important difference" in the push for comprehensive immigration reform.

Homeland Security Secretary Janet Napolitano told reporters Friday that the measure would have a substantial impact in terms of reducing the "trafficking of people, drugs, currency and weapons."

She also fired back at Republican critics of the White House's border control efforts, declaring that "the administration had already devoted more resources to the southwest border than at any point in American history."

The bill is funded in part by imposing higher fees on personnel companies that bring foreign workers into the United States.