Former Finance Minister Yoshihiko Noda won confirmation Tuesday as Japan's prime minister and immediately set to work on selecting his cabinet.

The new government's top priority is expected to be a long-stagnant economy, which has been battered by the effects of the March earthquake and tsunami. Mr. Noda will also have to deal with the continuing crisis at the Fukushima nuclear plant, which helped to undermine public support for his predecessor, Naoto Kan.

Mr. Noda told reporters ahead Tuesday's vote he expected to fill out a slate of ruling party and cabinet posts in time for his swearing-in as prime minister later this week.

The incoming Japanese leader also sought to quell controversy over a recent comment that Japan's World War II leaders were not war criminals under Japanese law, saying he will seek mutually beneficial relations with his country's Asian neighbors.

Mr. Noda, who will serve as acting prime minister until his swearing-in before Emperor Akihito, becomes Japan's sixth prime minister in the past five years. He has a reputation as a fiscal conservative who may be better able to work with the conservative opposition than Mr. Kan.

As finance minister, Mr. Noda supported tax reforms, including doubling the sales tax to pay for rising social security expenses, and working to bring the national debt under control.

Before his selection as president of the Democratic Party of Japan on Monday, Mr. Noda has said he would try to arrange a grand coaltion with the Liberal Democratic Party in order to address the massive challenges created by the March 11 earthquake and tsunami.

Mr. Kan announced his resignation late last week in the face of massive public dissatisfaction with his response to the March earthquake and the crisis at the Fukushima plant, which has been leaking radiation for more than five months.

The 54-year-old Mr. Noda will be one of the youngest Japanese leaders in recent years, and there are hopes that his age might bring about a generational shift in Japanese politics.