Hillary Clinton has announced she is to seek Democratic nomination in the US 2016 presidential campaign.
The former US secretary of state announced her bid for presidency on her Twitter account.
In a tweet Ms Clinton said "Everyday Americans need a champion, and I want to be that champion."
I'm running for president. Everyday Americans need a champion, and I want to be that champion. –H https://t.co/w8Hoe1pbtC
— Hillary Clinton (@HillaryClinton) April 12, 2015Moments before Ms Clinton confirmed her plans to run for president on Twitter, donors and supporters received an email from her campaign chairman, John Podesta, saying "It's official: Hillary is running for president."
The email said Ms Clinton will today travel to Iowa to start talking directly with voters.
In a video posted on her website Ms Clinton says "Americans have fought their way back from tough economic times, but the deck is still stacked in favour of those at the top."
"Every day Americans need a champion. And I want to be that champion."
Ms Clinton leads opinion polls among Democrats, some 60% of whom say they would vote for her in the primaries, according to the website RealClearPolitics.
Two other potential candidates, Senator Elizabeth Warren and Vice President Joe Biden, have not yet said they intend to run.
On the Republican side, Senators Rand Paul and Ted Cruz have already thrown their hats into the ring, with more candidates likely to follow, including Jeb Bush, former governor of Florida, brother to former US president George W. Bush and son of former US president George H.W. Bush.
A series of polls this year have consistently placed Ms Clinton ahead of every one of her potential Republican challengers, although the gap has narrowed in recent weeks.
Ms Clinton received endorsements from several European leaders, following the launch of her campaign for presidency.
"Good Luck @Hillary Clinton," tweeted French Socialist Prime Minister Manuel Valls, linking to her YouTube video.
German Foreign Minister Frank-Walter Steinmeier, a Social Democrat, wrote a lengthy good luck note in Germany's top-selling Bild daily, complete with strong praise for Ms Clinton's ability to deal with pressing world issues.
"I congratulate her on her decision to run for America and I wish her success," he wrote, reminiscing about his time working with Ms Clinton, who was secretary of state from 2009-2013.
"Hillary Clinton ... has also proven she has sure instincts in world crises - from Afghanistan to the Middle East. She knows Europe and understands our way of thinking," he said.
"With Hillary Clinton, there is a woman running who is a master of the craft of politics like few other people. Above all in foreign affairs," he added.
She was meet with criticism from Republican Senator Rand Paul who accused the Clinton Foundation of taking money from countries such as Brunei and Saudi Arabia, which, he said, made it hard for Ms Clinton to appear sincere on the issue of human rights.
Obama endorses Hillary Clinton for president on eve on campaign launch
Yesterday US President Barack Obama voiced support for Ms Clinton, saying she would make a fine president.
President Obama beat Ms Clinton for their party's nomination in 2008 after a gruelling campaign. He then won re-election four years later.
"She was a formidable candidate in 2008. She was a great supporter of mine in the general election. She was an outstanding secretary of state. She is my friend," President Obama said at a regional summit in Panama.
"I think she would be an excellent president."
The former first lady has set up a campaign HQ in New York.
It's @HillaryClinton's new presidential campaign HQ in Brooklyn, and look, it's beside Clinton St! #2016 @rtenews pic.twitter.com/zDecgcunw3
— Caitriona Perry (@CaitrionaPerry) April 12, 2015A bid to appear humble may have helped dispel doubts about Ms Clinton raised in recent weeks, after it was revealed that she used a private email account for her work when she was secretary of state from 2009 to 2013.
Detailed examinations of donations from foreign states and businesses to the Clinton Foundation when she was secretary of state have also raised questions about potential conflicts of interest.
