Graffiti artist Banksy has caused a storm of outrage in the U.S. by criticising the design of New York's newly-built World Trade Center, declaring: "The terrorists won."

The enigmatic guerilla artist has penned a blog dismissing the new One World Trade Center, which replaces the World Trade Center Twin Towers which collapsed in the 9/11 terrorist attacks on the city in 2001.

He writes, "It would be easy to view One World Trade Centre as a betrayal of everyone who lost their lives on September 11th, because it so clearly proclaims the terrorists won.

"You currently have under construction a one thousand foot tall sign that reads - New York - we lost our nerve.

"The attacks of September 11th were an attack on all of us and we will live our lives in their shadow. But it's also how we react to adversity that defines us. And the response? 104 floors of compromise?"

The piece, which was originally written as an editorial for the New York Times before it was rejected by editors, has angered many of those whose loved ones perished in the attacks.

Former Fire Department of New York Deputy Chief Jim Riches, who lost his son Jimmy, tells the New York Daily News, "He's insulting to everybody in New York, especially people that died that day."

Banksy had already angered many families of the 9/11 victims by his sketch Twin Towers in Tribeca, a wall stencil of the Twin Towers with an orange flower depicting the explosion caused by the airplane smashing into the complex.