Democratic presidential hopeful Barack Obama named veteran politician Joe Biden as his running mate today, his campaign confirmed.
Mr Biden, who chairs the US Senate's Foreign Relations Committee and has three decades of experience, will help the Obama campaign challenge the frequent criticism that it lacks foreign policy experience.
Mr Obama's choice of the 65-year-old Delaware senator as his vice presidential nominee was officially confirmed by a text message to supporters this morning as his campaign continues to embrace technology to garner support.
The announcement comes ahead of the Democratic Party's national convention in Denver, Colorado, next week, where Mr Obama is likely to be officially nominated as the party's presidential nominee.
Mr Biden will help strengthen the 46-year-old Illinois senator's foreign policy credentials.
Other potential vice presidential nominees, including Virginia governor Tim Kaine and Indiana senator Evan Bayh could have helped deliver a certain set of voters, or reinforce Mr Obama's message of change.
Mr Biden will now make a speech at the convention on Tuesday, but most US pundits agree that vice presidential candidates do not swing elections.
Mr Obama's two-month search for a running mate was conducted almost entirely in secret.
His Republican rival John McCain is expected to name his vice presidential nominee next week. Minnesota Governor Tim Pawlenty and former Massachusetts governor Mitt Romney are reportedly among those being considered.
Gaffe-prone Mr Biden is known for being talkative and is prone to making statements which get him in to trouble.
Last year, as a Democratic presidential hopeful, he said Mr Obama was "not yet ready" for the presidency, a remark which will now be seized upon by the Republican attack machine ahead of the general election on November 4.
Even before Mr Obama confirmed his selection this morning, McCain campaign spokesman Ben Porritt said: "There has been no harsher critic of Barack Obama's lack of experience than Joe Biden.
"Biden has denounced Barack Obama's poor foreign policy judgment and has strongly argued in his own words what Americans are quickly realising - that Barack Obama is not ready to be president."
Mr Biden, who dropped out of the presidential race in Iowa in January, is of Irish Catholic heritage but is in favour of abortion rights, a key issue in American elections.
He originally voted to authorise the war in Iraq, but has since become a persistent critic of the Bush administration's policies there.
Born in a working class family in Scranton, Pennsylvania, on November 20 1942, Mr Biden is not a household name, but was arguably the most well-known of those being considered by Mr Obama.
He first ran for the US Senate when he was 29 years old.
He was also the chairman of the Senate Judiciary Committee during two of the most contentious Supreme Court nomination battles of the past 50 years.
He led the opposition to the nominations of Robert H Bork, who was defeated, and Clarence Thomas, who was later confirmed.
Mr Biden married Neilia Hunter in 1966 and the couple had three children.
But his wife and 13-month-old daughter Naomi died in a car accident on December 18 1972, shortly after he was first elected to the US Senate.
His two sons, Joseph R "Beau" Biden III and Robert Hunter, were seriously injured, but Mr Biden was persuaded not to resign to look after them and was sworn into office from their bedside.
Both have since made full recoveries.
In 1977 he married Jill Tracy Jacobs, with whom he has one daughter Ashley, and he continues to commute 90-minutes each day from his home in the Wilmington suburbs to Washington, DC.