WASHINGTON: US President Barack Obama has made his first donation of USD 5,000 to his own campaign in an effort to motivate people to contribute to his reelection campaign, which lags behind the Mitt Romney campaign.

"Yesterday, I made my first donation to support this campaign," Obama said in an email to his supporters as his campaign's major fund raiser's deadline approached.

"On its own, what I gave won't be enough to surmount the unprecedented fundraising we've seen on the other side, both from our opponent's campaign and from the outside groups and special interests supporting him," he said.

According to election laws, USD 5,000 donation is the maximum an outside individual can donate directly to a political campaign.

Obama himself is not actually capped in his ability to donate. Anyone can give a far larger amount to the joint committees set up between campaigns and national political parties.

"Over the past two months, we have been outraised by our opponents. They've used that advantage to distort the truth and mislead people, over and over, on TV and the radio in battleground states. Tonight is one of the most critical fundraising deadlines we'll face," he said.

"If we win this election, it will be because of what you did in moments like this to close the gap," Obama said in another email.

Similar emails were sent by First Lady Mitchell Obama and Vice President Joe Biden.

"If we don't win this election, it will be because we didn't close the spending gap when we could. Because right now we're seeing that voters have a choice between two very different men," Biden said in his email.

"The only way someone like Mitt Romney - who's asking Americans to put him in charge of their taxes while refusing to come clean about his own, who wants to repeal Obamacare, end Medicare as we know it and give more tax breaks to billionaires who don't need them - defeats someone like Barack Obama, is if the other side spends us into oblivion," he said.