Saudi Arabia is constructing a 600-mile "great wall" along its border with Iraq to keep ISIS and other extremists at bay.

Former U.S. Ambassador to Saudi Arabia Robert Jordan revealed on "Happening Now" that the plans for the wall date back to 2003, when the late King Abdullah asked for U.S. planes to patrol the northern border to keep out drug traffickers and militants.

Jordan said that the U.S. didn't have the assets at the time, so for the last 7 to 8 years, Saudi Arabia has been tendering bids for some sort of border security system, finally beginning construction in September.

Jordan added that the high-tech, state of the art wall - which will have five layers of fencing, some of which are 125 feet high - isn't just intended to keep ISIS militants out, but also to prevent Iranian Shiite militants from entering Saudi Arabia through Iraq.

Jordan said that Saudi Arabia is also looking at doing the same thing with the country's 1,000-mile southern border with Yemen.

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This is happening as President Obama travels to Saudi Arabia this week to pay his respects to the royal family following the death of King Abdullah.

Obama will meet with the newly-appointed successor, King Salman, who inherits a number of challenges, including the rise of ISIS.

"The president needs to develop a personal relationship with King Salman," Jordan said. "So much of business in the Middle East is done on a personal level."

Jordan added that the relationship between the U.S. and Saudi Arabia comes down to security, fighting terrorism, maintaining a stable oil economy and maintaining credibility in the Muslim world.

"We can't do business in the Middle East without a strong relationship with Saudi Arabia."

Watch more above.