Independent Senator and former Democratic vice-presidential nominee Joseph Lieberman is endorsing Republican Senator John McCain's presidential bid.
Lieberman said his support for the Arizona Senator is based on McCain's military career and legislative experience and their common view of U.S. foreign policy.
Both men backed the U.S. invasion of Iraq in 2003 and have supported the war ever since.
Lieberman was former Vice President Al Gore's running mate in the 2000 presidential election. In the years since, the Connecticut senator distanced himself from the Democratic Party over the war in Iraq and became an independent, frequently voting with Republicans on foreign policy and national security issues.
The U.S. presidential campaign primary season is entering its final stage in the coming weeks, when voters in the states of Iowa and New Hampshire vote in early January for the candidates who will represent the Democratic and Republican parties in the November 2008 election.
Some information for this report was provided by AP.