Japanese Prime Minister Naoto Kan on Friday stepped down as president of the ruling party, paving way for selection of the disaster-hit nation’s sixth new premier in five years. Kan’s resignation comes after nearly 15 turbulent months in power during which his response to the March 11 earthquake, tsunami and resulting nuclear plant accident drew fierce criticism and sent his approval ratings plummeting. Kan told party lawmakers on Friday: “Once a new leader is elected, I will resign promptly as prime minister and my cabinet will resign.”