Japan’s defense minister said Tuesday that a decision on relocating an American air base on Okinawa may not be possible until at least November, further delaying resolution of a dispute that has hurt Tokyo’s relations with Washington. The defense minister, Toshimi Kitazawa, said a decision might have to wait until after a local governor’s election, as his government faces stiff local resistance to keeping the base, the United States Marine Air Station Futenma, on the island. Japan’s former prime minister, Yukio Hatoyama, had announced that Tokyo would move the base to a less populated part of the island. But Okinawans fiercely oppose the base, which has become a symbol of a heavy American military presence.