Japanese Prime Minister Naoto Kan has offered to resign in the coming months amid party defections that threaten to bring down his government in a parliamentary vote later Thursday.

Mr. Kan said at a meeting of his Democratic Party of Japan Thursday that he would like to hand over power to a younger generation once the prospects for dealing with the consequences of a March 11 earthquake become more clear.

Pressure has been building for the resignation of Mr. Kan amid widespread dissatisfaction with his handling of the earthquake clean-up and the resulting Fukushima nuclear crisis. Dozens of party members plan to join the opposition in a Thursday no-confidence vote that is considered too close to call.

Analysts say the opposition needs 82 DPJ votes to pass the motion. NHK national television said it has been told by about 70 members that they plan to vote for the motion, and as many as 40 others are undecided.

Mr. Kan has said he will dissolve parliament and order new elections if the vote succeeds.

The opposition submitted the motion Wednesday evening, charging that Mr. Kan has failed to show leadership in the handling of the world's worst nuclear crisis since Chernobyl. Opinion polls show the public shares that view, with Mr. Kan's approval rating consistently standing below 30 percent.

But few look forward to new elections, which would complicate Japan's efforts to deal with the massive job of rebuilding after the nation's worst earthquake and a resulting tsunami. The country is also struggling to cope with a massive public debt.

Many members of Mr. Kan's party would prefer to form a coalition with the opposition Liberal Democratic Party, enabling the country to confront its challenges with a united government.

In his remarks Thursday morning, Mr. Kan said he feels that he still must fulfill his obligations to the Japanese people.

But, he said, once the prospects for dealing with the earthquake become clear and he has been able to fulfill his obligations to a significant degree, he would like to hand over many of his responsibilities.