As the Japanese troops gathered west of the Matanikau, the U.S. forces strengthened their Lunga defenses. On 14 September Vandegrift moved another battalion, the 3rd Battalion, 2nd Marine Regiment (3/2), from Tulagi to Guadalcanal. On 18 September an Allied naval convoy delivered 4,157 men from the 3rd Provisional Marine Brigade (the 7th Marine Regiment plus a battalion from the 11th Marine Regiment and some additional support units).