The widely expected announcement came on Monday, when US president Barack Obama (photo, from aljazeera.net) said that in 2012 he wants to stand for a second term in office.
He made the announcement in an e-mail sent to supporters and a video released on his official website and posted on YouTube.
“Today, we are filing papers to launch our 2012 campaign,” he said.
He explained that as his administration and supporters across the country “fight to protect the progress we’ve made – and make more – we also need to begin mobilising for 2012, long before the time comes for me to begin campaigning in earnest”.
“So even though I’m focused on the job you elected me to do, and the race may not reach full speed for a year or more, the work of laying the foundation for our campaign must start today.”
Mr Obama’s supporters will start shaping a new organisation in coming days, and the US president added : “And I’ll need you to help shape our plan as we create a campaign that’s farther reaching, more focused, and more innovative than anything we’ve built before.”
For the next 20 months before the election President Obama will now work to convince US citizens that he has brought the change he promised them in his first presidential campaign in 2008.
In the 2008 election, Mr Obama raised a record $750m but for this campaign political observers expect him to raise an unprecedented $1bn.
Although several Republicans are considering running against the current president, none have made their candidacies officials, while early polls show Mr Obama leading potential Republican rivals.
Among those thought likely to run are Mitt Romney, Mike Huckabee, former House Speaker Newt Gingrich and Haley Barbour, currently governor of Mississippi.
Even though she’s still very popular with some Republicans, Sarah Palin divided opinion nationally.
For now the only candidate who formally declared his candidacy is former governor of Minnesota Tim Pawlenty.
According to polling by the Pew Research Center, President Obama, who took office in January 2009, is in a similar position at this stage to George W Bush and a stronger position than Bill Clinton. Both of then won re-election.
In polling carried out in March, some 47% of registered voters said they would like to re-elect Mr Obama, while 37% said they would vote for a Republican candidate.