On the call, Mr. Trump was asked for details about how long it would take to round up illegal immigrants living in the U.S., with the questioner asking if five or ten years was an appropriate timeframe. Mr. Trump said his two year benchmark could be met with “really good management.”

“We have to get them out. If we have wonderful cases, they can come back in but they have to come back in legally,” Mr. Trump said in an audio clip posted on YouTube Thursday night by a person on the call.

Mr. Trump’s plan has been denounced by Democrats and many rival Republicans, who have called it impractical and immoral, among other criticisms.

Mr. Trump said he would remove illegal immigrants from the country “so fast that your head will spin,” and long before he could embark on his plan to build a wall spanning the 1,900 mile border between the U.S. and Mexico.