Mitt Romney has conceded defeat in the U.S. presidential election, The Associated Press reports.

The Republican nominee told supporters he would pray for Barack Obama's success in leading the nation. He also thanked his running mate Paul Ryan, saying the Wisconsin congressman had a bright future in the GOP.

Romney lost nearly all the major battleground states to Obama including Ohio, the hardest fought prize.

The former Massachusetts governor said it was time to put aside partisan bickering and work together for the good of the country.