The timing of Prime Minister Naoto Kan's resignation caused a political storm Friday, after he indicated he may stay put for months before actually exiting.

During a news conference late Thursday night, Kan indicated he will step down once the government has successfully brought the troubled reactors at the Fukushima No. 1 plant to "cold shutdown" status.

But according to an earlier road map by Tokyo Electric Power Co., the utility aims to achieve this by January, whereas many of Kan's enemies had expected him to step down as early as the end of this month.