The initial American response to these escalatory measures was to resume construction of battleships displacing 35-38,000 tons with nine 16-inch/45-caliber guns, but with greater speed and endurance. Six new battleships (BB-55 through BB-60) of the North Carolina and South Dakota classes would be launched in 1940-42 and fought in World War II. However, these battleships had a maximum speed of only 27-28 knots, could not keep up with the fast carriers or the Japanese fast battleships, and were no match for the bigger treaty-busting battleships reportedly being built in Japan.