On 2 June 2010, Hatoyama announced his resignation before a party meeting and officially resigned two days later. He cited breaking a campaign promise to close an American military base on the island of Okinawa as the main reason for the move. On 28 May 2010, soon after and because of increased tensions after the possible sinking of a Korean ship by North Korea, Hatoyama had made a deal with U.S. President Barack Obama to retain the base for security reasons, but the deal was unpopular in Japan. He also mentioned money scandals involving a top party leader, Ozawa, who resigned as well, in his decision to step down. Hatoyama had been pressured to leave by members of his party after doing poorly in polls in anticipation of the July upper house election. Naoto Kan succeeded Hatoyama as the next President of DPJ and Prime Minister of Japan.