The border security measure will now fund the hiring of 1,500 new Border Patrol agents, plus 250 Immigration and Customs Enforcement agents and 250 Customs and Border Protection officers.

The specific aim is to put both more agents and equipment along the US-Mexican border, which is all part of a White House push to beef up border security to keep illegal immigrants out of the US workplace, and to block the running of guns and drugs across the border.

After signing the bill, the president hosted an iftar dinner Friday evening in celebration of the Islamic holy month of Ramadan in the White House State Dining Room.

Former President George W. Bush began the tradition of holding annual iftar dinners during his eight years in office. Muslim diplomats and ranking members of the Muslim American community were invited, with prayers being led by Imam Abuhena Saifulislam, a Navy chaplain.

The border security bill, meanwhile, will take effect immediately and funding will include  additional unmanned surveillance planes along the border area.

Immigration has been the subject of contentious arguments this year, as the southwestern border state of Arizona enacted a new law in April requiring police officers to check a person’s immigration status while enforcing other laws.

A judge put that provision on hold, along with one requiring immigrants to carry their immigration documents with them at all times. Opponents say the law will lead to racial profiling by police.

The bill was of such importance that the Senate took a short break from their monthlong vacation to return to Washington for a special session Thursday to pass the border security package.

The bill will also fund increased intelligence and unmanned surveillance vehicles, or drones, along the border, and will give $196 million to the Department of Justice to pay for US attorneys, legal expenses, and a federal prison system for illegal immigrant felons, among other security measures.

The border security bill was welcomed with bipartisan support, as immigration reform is likely to be a hot topic of debate on the campaign trail for members of Congress.

But some Republicans quickly mocked the security bill, saying they don’t trust President Obama’s broader reform effort that they believe will provide a path to citizenship for illegal immigrants.

In another development, the Obama administration said attempts to change the US constitutional amendment that grants automatic citizenship to people born in the United States are “just wrong.”

Homeland Security Secretary Janet Napolitano said she is surprised that Republican congressional leaders are joining a push to reconsider the 14th Amendment instead of working with Democrats on comprehensive changes in immigration rules.

White House spokesman Robert Gibbs said President Obama agrees with Napolitano’s position. Senate Republican leader Mitch McConnell has said he supports holding hearings on the 14th Amendment, although he emphasized that Washington should remain focused on border security.