Trump Again Cites Israel, Says 'Walls Work'

U.S. President Donald Trump told a conference of police chiefs that Israel's barrier along the border with Egypt proves that walls do, indeed, stop illegal immigration.

U.S. President Donald Trump speaks to members of the law enforcement at the Major Cities Chiefs Association (MCCA) Winter Conference in Washington, U.S., February 8, 2017.

President Trump has doubled down on one of his more controversial campaign promises: his plan to build a wall spanning the length of the U.S.-Mexico border to curb illegal immigration.

Speaking at a conference of police chiefs in Washington on Wednesday, the president insisted: “The wall is getting designed right now. And it will be a real wall.” 

During the speech, Trump once again cited Israel as evidence that the border wall will indeed stop illegal immigration.

"Just ask Israel about walls. Do walls work? Just ask Israel. They work. If it’s done properly," the president said.

Trump has made this claim repeatedly in the past and Prime Minister Benjamin Netanyahu took to Twitter in late January to back-up Trump's claim. 

"President Trump is right. I built a wall along Israel's southern border. It stopped all illegal immigration. Great success. Great idea," Netanyahu tweeted.

“A lot of people say, ‘Oh, oh, Trump was only kidding with the wall.’ I wasn't kidding. I don't kid. I don't kid,” added Trump.

The president's comments came a day after the new secretary of Homeland Security, General John F. Kelly, told Congress that building the wall could take two years and cost billions of dollars, reported the Los Angeles Times.