FACE-OFF. US Republican Presidential candidate Mitt Romney and US President Barack Obama slug it out for votes in one of the "swing" states, Ohio. AFP PHOTO/Emmanuel Dunand (L) / Jewel Samad (R)

WASHINGTON, United States - US President Barack Obama maintains a lead over his Republican rival, Mitt Romney, in the key battleground states of Ohio and in Florida, a new public opinion poll has found.

The NBC News/Wall Street Journal/Marist survey made public Friday indicated that 3 days before Tuesday's vote, Obama holds a 6-point advantage over Romney among likely voters in Ohio - 51% to 45%.

In Florida, the president enjoys the support of 49% of likely voters compared to Romney's 47%.

Victories in these two states will be key to winning the White House on Tuesday. Ohio awards 18 electoral college votes and Florida 29.

A candidate needs 270 electoral college votes to win a second term.

The NBC/WSJ/Marist poll of Florida had a margin of error of plus-minus 2.5 percentage points while the survey of Ohio had a margin of sampling error of plus-minus 3.1 percentage points. - Agence France-Presse

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