Newt Gingrich, whose GOP competitors accuse him of being soft on illegal immigration, pledged Thursday, if elected president,  to build a double fence along the Mexican border during his first days in the White House.  

“We haven’t been able to build a fence on the border because we have not been a serious country,” the former House speaker said at an event in Iowa, before he signed his name to the pledge sponsored by the activist group Americans for Securing the Border.

Gingrich has maintained that the border needs securing but has also suggested that some of the 11 million illegal immigrants living in the U.S. be permitted to stay in the U.S. legally. Some of his competition, including Minnesota Rep. Michele Bachmann, has called that policy “amnesty.”

Bachmann was the first candidate, and is the only other 2012 contender to sign the pledge.

The candidates pledge “to support and speedily expedite the construction of a date-certain, secure multi-layered fence (fence locations to be specified by the Border Patrol or Homeland Security) across the U.S.-Mexican border to be completed prior to the end 2013.”