With results for only three states pending, US President George W Bush is leading his Democratic rival John Kerry 254 to 252 electoral votes.
In the American electoral system, each state is assigned a certain number of votes based on the size of its population. These votes comprise the electoral collage, which elects the president.
A candidate who wins the maximum votes in a state wins all the electoral votes assigned to that state.
Of the 50 states, Bush has won the electoral votes of 28 states while Kerry has 19 and the District of Columbia. Bush is leading with 254 of the minimum number of electoral votes (270) required to win the presidency.
The results of the voting in Iowa, New Mexico and Ohio are yet to be declared.
Also See:
How the US electoral system works