China on Friday congratulated Kan's inauguration as the new Japanese prime minister.

Premier Wen Jiabao sent Kan a congratulatory message on Friday on his election.

China is willing to work together with Japan to further develop mutually beneficial Sino-Japanese strategic relations, Wen, who just paid a visit to Tokyo earlier this week, said in his message.

Kan, Japan's sixth prime minister in four years, also pledged to confront domestic problems linking money and politics. He stressed the need for fiscal discipline while trying to spur economic growth.

While his political philosophy is hard to neatly categorize, analysts and fellow lawmakers agree that his personal traits and background as a civic activist and proactive Cabinet minister set him apart from Hatoyama.

"He has a record of acting on the basis of his beliefs and not backing down," said Tobias Harris, a political analyst who once worked as an aide to a lawmaker in Japan. "Those are good signs for a prime minister and I think those are qualities that Hatoyama did not have."

In a written candidate's statement on Friday, Kan identified economic recovery as the biggest challenge facing Japan, whose economy will almost certainly be overtaken in size by China this year. While exports and factory output are rising, unemployment and deflation are worsening.

"I will tackle and pull Japan out of deflation through comprehensive measures from the government and the Bank of Japan," Kan said in the statement.

He pledged to resume fiscal reforms and work toward sustainable finances, including possible tax reform, to ensure a strong social security system for Japan's aging population.

But some analysts question whether Kan will be able to salvage public support for his party or enact real change.

"It's a big mistake to think you can win the elections just by changing the cover of the book," said Yasunori Sone, a political science professor at Keio University.

"It's unclear what he is keeping of Hatoyama's policies and what he is hoping to change."

Nevertheless, the Democrats are hoping that the resignations on Wednesday of Hatoyama and the party's No 2, Ichiro Ozawa - both of whom were embroiled in political funding scandals - will give it a fresh face for the July elections.

A poor performance in the upper house elections, where half the seats are up for grabs, is not expected to threaten the Democrats' grip on power because they command a large lower-house majority. But heavy losses will likely force the party to woo new coalition partners to ensure a smoother passage of bills, analysts said.