"I am here to tell you that this will be a close race and you cannot take it for granted," Obama told several thousands of his supporters at an election rally.
Donald Trump has backed out of a televised debate against Democrat Bernie Sanders just two days after agreeing.
Here are 7 things you need to know, including some you probably didn't know, about this historic debate.
In a big relief to Hillary Clinton, the Federal Bureau of Investigation on Tuesday ruled out charging the Democratic presidential candidate over allegations that she violated rules by using a private email server while she was United States Secretary of State.
United States President Joe Biden and Vice President Kamala Harris laid a wreath at the Tomb of the Unknown Soldier in Arlington National Cemetery.
He said his administration will spare 'no resources or expense in this effort' to investigate who sent the packages.
Trump had been a leader of the 'birther' movement that questioned Hawaii-born Obama's citizenship.
Trump said his Democratic rival Clinton would pay the price of her email scandal in the November general elections.
They were spotted together at fashion designer Ralph Lauren's 50th anniversary show.
Hillary Clinton, Donald Trump and John Kasich scored major victories on Tuesday that significantly reshaped the presidential race while a big loss in Florida prompted Marco Rubio to drop his White House bid.
Speaking at a summit organised by the US-India Business Council in Washington DC, Secretary of State Hillary Clinton pushed for stronger economic and diplomatic ties between the United States and India.
The US State Department is reviewing whether former Secretary of State Hillary Clinton violated any policies of the federal government while using her private emails for official use, a media report has said.
The Congress party has claimed credit for the extradition of Tahawwur Rana, an accused in the 2008 Mumbai terror attacks, from the US, saying the Modi government did not initiate the process and merely benefited from the "mature, consistent and strategic diplomacy" begun under the UPA. Former Home Minister P Chidambaram said the government did not secure any breakthrough to make the extradition possible, nor is it the result of any grandstanding. He added that it was a testament to what the Indian state can achieve when diplomacy, law enforcement and international cooperation are pursued sincerely and without any kind of chest-thumping. Chidambaram detailed the UPA government's efforts in securing Rana's extradition, citing the registration of a case against him in 2009, diplomatic pressure on Canada and the US, and continued efforts despite legal setbacks. He highlighted the role of the UPA in securing Rana's conviction for other terrorism-related offences and the cooperation between the US and Indian agencies in gathering evidence and securing his extradition. The Congress leader further stated that it was the UPA's groundwork that paved the way for Rana's extradition, even after the change in government in 2014.
The fuzziness of Trump's economic blueprint remains the biggest risk.
"I will keep you in suspense," said the Republican as he refused to commit to accepting the election result if he loses, in the third debate against Hillary Clinton.
Palestinian and Israeli leaders met in Washington under the United States-brokered direct peace talks after 20 months hiatus, with Secretary of State Hillary Clinton pressing them to forget the long history of failed parleys and overcome "suspicion and skepticism".
US Secretary of State Hillary Clinton today warned that "activities" by extremist elements in Pakistan pose a "direct threat" to government in Islamabad as well as security of America and other nations.
The United States on Sunday said it may use nuclear weapons if the country comes under biological attacks, according to a repot in Dawn. Secretary of State Hillary Clinton said on Sunday the US could not rule out using nuclear weapons, saying in that case "all bets are off."
Here are some of the most unforgettable lines from the first presidential debate.
Voicing India's disappointment over Pakistan not prosecuting perpetrators of the Mumbai attacks, Home Minister P Chidambaram today made it known to Secretary of State Hillary Clinton that it expects tangible action on the terror issue.
The animated image, which the president retweeted on Sunday, also shows Clinton tripping and falling after being hit in the back as she boards a plane in 2011 as the secretary of state, CNN reported.
Obama, aiming to become the first black US president in history, garnered roughly twice the votes received by Hillary in Nebraska and Washington, which have 24 and 78 delegates respectively who will go to the Democratic National Convention to elect the party's nominee for the presidential election.
US Secretary of State Hillary Clinton has asked Sri Lankan President Mahinda Rajapaksa to devise a political solution to the ongoing ethnic conflict in the country.
Fazul Abdullah Mohammed was stopped at a roadblock manned by forces of the Somali transitional government, but he sped through, forcing the troops to shoot him.
"The event is invitation-only for friends and supporters of the Trump-Pence campaign," the Trump campaign said.
Deepika bonded with Aishwarya. Anil Kapoor and wife mingled with the Thackerays.
President Barack Obama and Secretary of State Hillary Clinton were the "most admired" man and woman in the United States for 2010, a new survey has revealed.
Less than 24 hours after the historic re-election of Barack Obama as the US president, speculation has begun in Washington, DC, as to who would be the Democratic party nominee for the 2016 presidential elections
In effect, he became the first former president to get the nomination for the top office after being convicted of a felony.
The billionaire from New York, who continually claimed that the election was "rigged" before his victory, insisted in a statement that the results should be "respected, instead of being challenged and abused".
And voters could also be asked to participate in "referendums" on issues before the lawmakers in that particular state.
The Trump Organisation has a secret server registered to Trump Tower that has been covertly communicating with a Russian bank, a media report said, in the latest allegation of questionable links between Donald Trump and Russia just a week ahead of the presidential polls.
To read Raymond Vickery's hugely interesting book while US Secretary of State Hillary Clinton is still on Indian soil reminds one of the great distance India and the US have travelled since the 1998 nuclear tests.
Clinton and Sanders, meeting for the debate in Brooklyn just days before the crucial presidential primary in New York on April 19, minced no words as they attacked each other.
US Secretary of State Hillary Clinton on Thursday hosted a delegation of lawmakers, civil rights activists and some of this country's leading musicians, including jazz great Herbie Hancock, on the eve of their setting off on a trip to India to retrace the late Rev. Martin Luther King, Jr's visit 50 years ago, and to commemorate the influence Mahatma Gandhi had on this civil rights icon and the passive resistance movement he founded.
The second debate soon turned ugly with the Republican nominee going on the offensive with personal attacks, but Democratic rival accuses him of diverting attention from the lewd tapes.
The lawmakers who have written a letter to Clinton in this regard include, Senate Intelligence Committee Chairman Dianne Feinstein and Vice Chairman Saxby Chambliss and House Intelligence Committee Chairman Mike Rogers and Ranking Member Dutch Ruppersberger.
A United States lawmaker has asked Secretary of State Hillary Clinton to reconsider the government's decision against issuing a diplomatic visa to Gujarat Chief Minister Narendra Modi, drawing strong reactions from the Indian American Muslim community in Washington. Congressman Joe Walsh, a right-wing conservative Republican and a tea party favourite, has written a letter to Clinton, requesting her to consider granting a diplomatic visa to Modi.
United States Secretary of State Hillary Clinton has strongly condemned the attacks on journalists covering the ongoing situation in Egypt, terming it as a "violation of international norms".