Washington, Jun 4 (IANS/EFE): Lincoln Chafee, a former senator and ex-governor of Rhode Island has officially announced his candidacy for the US' presidential nomination in 2016, thus becoming the fourth contender.

Chafee, who has spent most of his political career in the Republican Party until switching parties two years ago, selected George Mason University in Arlington, Virginia, as the site where he wanted to launch his campaign, joining Hilary Clinton, former Maryland Gov. Martin O'Malley and Vermont Sen. Bernie Sanders in vying for the Democratic nomination, EFE reported.

The new candidate promised to get the country out of onerous wars so that the money being spent there can be allocated to other matters, such as public health, fighting climate change, infrastructure and job policies.

He was a senator for Rhode Island (1999-2007) and the state's governor (2011-2015) and joined the Democratic Party in 2013, after having played an important advisory role in President Barack Obama's election campaign.

During his years in the US Senate, Chafee often voted with the Democrats and was the only Republican senator who voted against the Iraq war.

He said in his declaration speech before international relations students at George Mason University on Wednesday that he learned in the first few months of the George.W. Bush administration not to trust the then-president or then-Defence Secretary Dick Cheney.