With 96 percent of the nation's precincts reporting, Democratic candidate John Kerry has won 53,582,115 votes, or 48 percent, while George W. Bush has claimed 57,220,248 votes, or 51 percent, showed the latest nationwide election returns reported by the Associated Press.
According to the tally, Kerry has won 252 electoral votes from 20 states, including the District of Columbia, compared with 254 electoral votes from 28 states for Bush. To win the presidency, 270 of the 538 electoral votes are needed.
The campaign of US Democratic candidate John Kerry early Wednesday refused to concede defeat in the crucial state of Ohio, which carries 20 electoral votes.
"The vote count in Ohio has not been completed. There are more than 250,000 remaining votes to be counted. We believe when they are, John Kerry will win Ohio," said Kerry campaign manager Mary Beth Cahill in a statement.
Earlier, the Fox and NBC TV networks projected that Bush had won the key battleground state. The win would make Bush just one electoral vote short of the 270 needed to win the presidency.
States and votes Bush, Kerry have won as of 01:40 a.m. (0640 GMT)
The followings are the names of states and the number of their electoral votes won by US Republican candidate George W. Bush and Democratic Senator John Kerry as of 01:40 a.m. Wednesday (0640 GMT) in the 2004 presidential election, based on projections by major television networks.
A candidate needs a total of 270 electoral votes to win the presidency.
States won by Bush Number of electoral votes
Indiana 11
Kentucky 8
Georgia 15
West Virginia 5
Alabama 9
Oklahoma 7
Tennessee 11
Virginia 13
North Carolina 15
South Carolina 8
Kansas 6
Nebraska 5
North Dakota 3
South Dakota 3
Texas 34
Wyoming 3
Louisiana 9
Mississippi 6
Utah 5
Arkansas 6
Missouri 11
Idaho 4
Arizona 10
Montana 3
Florida 27
Colorado 9
Alaska 3
Total 249
States won by Kerry Number of electoral votes
Vermont 3
Delaware 3
Connecticut 7
District of Columbia 3
Illinois 21
Maryland 10
Massachusetts 12
New Jersey 15
Maine 4
New York 31
Rhode Island 4
Pennsylvania 21
California 55
Oregon 7
Washington 11
New Hampshire 4
Total 211
Backgrounder: Electoral College, key mechanism of US presidential election
Americans do not vote directly for presidential candidates. Instead, after ballots are tallied in each state, state representatives, called electors, vote based on the state tallies in an Electoral College, a system which has been operating since 1788.
According to the system, a state's number of electoral votes equals the number of senators and House representatives combined from that state. As the number of House representatives are based on the size of population of each state, the number of electors varies from state to state.
California, the largest state, has 55 electoral votes, while the sparsely populated Alaska has only three. The District of Columbia, which has no representatives in Congress, has three electoral votes.
In all but two states -- Nebraska and Maine -- winner of the popular vote (the total number of votes cast by people in a given state) takes the state's total allotment of electoral votes.
In Nebraska and Maine, five out of the total nine votes are distributed based on voting in congressional districts, rather than in the state as a whole.
Under the Electoral College system, it is possible that a candidate who wins the popular vote may actually lose the election if he/she wins fewer electors' votes.
The Electoral College meet and officially vote for president and vice president on the first Monday following the second Wednesday in December in each presidential election year.
A majority of 270 electoral votes out of a total of 538 is needed for victory.
If no candidate receives a majority, the House of Representatives -- one of two houses of Congress -- must determine the winner from the three candidates who receive the most votes in the electoral college.
In 1824, John Quincy Adams did not win a majority in the vote and was elected president by the House of Representatives in this way.
The president and vice president take their oath and assume office on Jan. 20, following the election. Presidential election is held every four years and the president can be re-elected only once.
The Electoral College is established and runs on basis of the US political system, in which three separate branches -- executive, legislative and judicial -- check and balance each other under the Constitution, and also results from compromises and concessions of different interest groups.
In recent years, there have been calls for reform, but no material moves have been taken.
The following is a summary of electoral votes held by each state and the District of Columbia for the presidential election.
State Electoral votes
Alabama 9
Alaska 3
Arizona 10
Arkansas 6
California 55
Colorado 9
Connecticut 7
Delaware 3
Dist. Of Columbia 3
Florida 27
Georgia 15
Hawaii 4
Idaho 4
Illinois 21
Indiana 11
Iowa 7
Kansas 6
Kentucky 8
Louisiana 9
Maine 4
Maryland 10
Massachusetts 12
Michigan 17
Minnesota 10
Mississippi 6
Missouri 11
Montana 3
Nebraska 5
Nevada 5
New Hampshire 4
New Jersey 15
New Mexico 5
New York 31
North Carolina 15
North Dakota 3
Ohio 20
Oklahoma 7
Oregon 7
Pennsylvania 21
Rhode Island 4
South Carolina 8
South Dakota 3
Tennessee 11
Texas 34
Utah 5
Vermont 3
Virginia 13
Washington 11
West Virginia 5
Wisconsin 10
Wyoming 3