With a height of 1,776-feet (541-m), the new World Trade Center tower in New York was on Tuesday declared as the tallest tower in the US, surpassing Chicago's Willis Tower (442-m). Height of the needle (124-m) atop the skyscraper was also taken into account when measuring WTC's height. Dubai's Burj Khalifa is the tallest building in the world at 828-m.