US President Barack Obama has announced his intention to stand for a second term in office in 2012.
Mr Obama's team released a video on his official website and sent an e-mail to supporters announcing his plans.
The president has an online network of millions of Americans and his web campaign was widely seen as a key plank of his election success in 2008.
The announcement was widely expected, and his campaign team are set to file election papers this week.
In an e-mail to supporters, Mr Obama said the campaign would start small and grow over time, "with people organising block-by-block, talking to neighbours, co-workers, and friends".
"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."
Unveiling a new look for Mr Obama's campaign website, his team told supporters: "The idea is to improve upon what's worked for the past four years, scrap what hasn't, and build a campaign that reflects the thoughts and experiences of the supporters who've powered this movement."
After the 'shellacking'
A number of Republican presidential hopefuls are expected to seek the nomination to run against Mr Obama.
