WASHINGTON (Reuters) – U.S. President Barack Obama said on Thursday Republican presidential candidate Donald Trump’s plan for mass deportation of illegal immigrants is unrealistic.

“The notion that we’re gonna deport 11, 12 million people from this country – first of all, I have no idea where Mr. Trump thinks the money’s gonna come from. It would cost us hundreds of billions of dollars to execute that,” Obama said in a White House interview with ABC News, according to excerpts released by the network.

“Imagine the images on the screen flashed around the world as we were dragging parents away from their children, and putting them in what, detention centers, and then systematically sending them out,” the president said. “Nobody thinks that is realistic. But more importantly, that’s not who we are as Americans.”

Trump, a real estate billionaire who has been leading in opinion polls among candidates for the Republican nomination in the 2016 election, calls for building a wall along the U.S. border with Mexico and deporting all illegal immigrants.

The immigration issue has driven a wedge between Hispanics, a voting bloc with increasing clout, and Republicans, many of whom take a hard line on illegal immigration, to the benefit of Obama’s fellow Democrats. Most of the estimated 11 million illegal immigrants are Hispanic.

Obama said there has always been a streak of anti-immigrant sentiment in the United States. “We don’t want, I think, a president or any person in a position of leadership to play on those kinds of fears,” he told ABC.

(Reporting by Mohammad Zargham; Editing by Chris Reese)

U.S. President Barack Obama in Washington October 23,  2015.  REUTERS/Kevin Lamarque