Japanese Prime Minister Naoto Kan won the presidential election of the ruling Democratic Party of Japan (DPJ) on Tuesday to remain as the country's leader.

Kan collected 721 points out of the total 1,222 points up for grabs, while DPJ kingpin Ichiro Ozawa got only 491 points.

"I am determined to revive Japan's economy and keep party unity within the DPJ," Kan said after the election victory.

"The election is over now. It's time for all the members of the DPJ to unite and keep the party's pledges," he added.

The DPJ's 411 members of parliament, local DPJ lawmakers and party members chose between the two men.

Reports suggest MPs, whose votes carry much more weight, are evenly split between the two men, while Kan was way ahead of Ozawa, the former DPJ secretary-general, in terms of support from local DPJ lawmakers and party members. Kan secured 249 points from party members and supporters, in contrast with Ozawa's 51 points.

The voting began after the two contenders deliver their final 15-minute speeches at an extraordinary party convention at a Tokyo hotel on Tuesday afternoon.

In his speech, Kan repeated the top priority is to boost the nation's economy out of decades-long deflation and creating employment.

"We will be able to overcome this stalemate if we have public trust," Kan said.

Ozawa, meanwhile stressed the need to wrest control from bureaucracy and have politicians take the lead, saying, "If we don 't change politics now, it will be too late (for Japan)."

On the diplomatic front, Ozawa said, "Japan-U.S. ties are the most important bilateral relations. Next to the Japan-U.S. ties, Japan-China ties and Japan-South Korea ties are important," he said.

Whoever wins party leadership election will become the prime minister, because the DPJ has a majority in the lower house of parliament.

Kan was elected in June after Yukio Hatoyama stepped down over failing to follow through on a promise to move an unpopular U.S. military base from the island of Okinawa.

Ozawa, often dubbed "the shadow shogun", announced his leadership challenge in August after DPJ lost seats in upper house elections in July, a result blamed in part on Kan's stance on raising consumption tax in a bid to reduce Japan's massive public debt.

Ozawa is widely seen as the main strategist of the DPJ's historic victory in the general election in August 2009, breaking the Liberal Democratic Party's almost consecutive ruling for over half a century.

However, Ozawa has since become embroiled in a political fund scandal. He is possibly to be indicted over the case.