Washington, July 3 (IANS): Former Virginia senator Jim Webb has announced his candidacy for the Democratic Party's US presidential nomination via email and his Web page.

"I understand the odds, particularly in today's political climate where fair debate is so often drowned out by huge sums of money," said the ex-lawmaker who, however, said he had decided to run to try and "unite" the country.

He called in his announcement on Thursday for a "new approach" to solve the biggest problems confronting the nation and a leader who can "shake the hold of (the) shadow elites on our political process".

Although his name has been mentioned for months as a potential Democratic contender for the party's presidential nomination, whether or not he would run was not clear until he decided to involve himself despite the strong criticism he had expressed about the campaign financing system and the management of campaigns, Efe news agency reported.

"Our fellow Americans need proven, experienced leadership that can be trusted to move us forward from a new president's first days in office," he said in his announcement.

His message, directed mainly to his supporters, emphasised his military experience as a troop commander in the Vietnam War and as assistant defense secretary and secretary of the Navy during the 1981-1989 presidency of Ronald Reagan.

Webb becomes the fifth Democrat to throw his hat into the ring, along with former Maryland governor Martin O'Malley, Vermont Senator Bernie Sanders, former Rhode Island senator Lincoln Chafee and the hot favourite: former secretary of state Hillary Clinton.

In a clear allusion to Clinton's decisions while she was a senator and head of the State Department, Webb said that he would not have voted to involve the US in war in Iraq if he had been a senator at that time, adding that he would not have used military force in Libya during the Arab Spring.