According to Heritage Foundation poverty expert Robert Rector, the illegal immigrants recently provided deportation relief by President Barack Obama will cost taxpayers $2 trillion over the course of their lifetimes, he said during an interview with Breitbart News on Monday.

"The net cost - which is total benefits minus total benefits paid in - of the amnesty recipients I estimate will be around $2 trillion over the course of their lifetime," Rector said, adding that his calculation is based on the assumption that the immigrants will both live and participate for an average of 50 years.

With Obama's plan putting the immigrants into the Social Security and Medicare programs, and with the average immigrant having a 10th grade education level, amnestied immigrants are expected to take out much more than they will contribute, according to Breitbart.

"Given their expected earnings...they will draw about three dollars worth of benefits out of those programs over their lifetimes for every dollar they put into them. But the overall cost in outlays will be around a trillion dollars for those programs alone," Rector stated.

A White House official confirmed to The Washington Post Tuesday that millions of illegal immigrants will, in fact, be eligible to receive a "wide array of other federal benefits," in addition to Social Security and Medicare. 

"If they pay in, they can draw," said White House spokesman Shawn Turner, noting that the some 5 million immigrants will not be eligible for other federal benefits such as Obamacare, student financial aid, food stamps or housing subsidies.

Rector, though, believes that within a dozen or so years - either through legislation or executive action - illegal immigrants will be granted access to welfare programs.

If there isn't such executive or legislative action, Rector says that once the citizen children of the amnestied immigrants turn 21, they could potentially petition to have their parents obtain green cards.

"After 5 years with a green card status they are eligible for all the welfare programs," he said. "Even if they are waiting 10 or 12 years to get access to these programs, that is still a trillion dollar cost once they begin to get into them."

According to a 2013 paper by Rector published on the Heritage Foundation site, if the entirety of the 11.5 million undocumented immigrants were given amnesty, "they would generate a lifetime fiscal deficit of $6.3 trillion."

Many critics worry that adding millions of immigrants to the Social Security pool will "help make Social Security solvent."