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.

Currently, incumbent Republican President George W. Bush leads Kerry by 51 percent to 49 percent in the popular vote in Ohio.

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.