Photo taken on Oct. 5, 2012 shows that U.S. President Barack Obama speaks during a campaign rally in Fairfax, Virginia, the United States. Barack Obama wins U.S. presidential elections. (Xinhua/Fang Zhe)

The incumbent Barack Obama has won re-election in the U.S. presidential race, TV networks projected on Tuesday.

According to projections by major TV networks including Fox News, CNN and MSNBC, Obama has passed the threshold of 270 electoral votes needed to win the presidency, handily beating his Republican challenger Mitt Romney.

Obama was projected to have won several key swing states, including Ohio, Pennsylvania, Wisconsin, Iowa and New Hampshire, while Romney only won North Carolina. Florida and Virginia remained too close to call.

Obama easily grabbed a host of "deep blue" states including California, Illinois and New Jersey, while Romney prevailed in "deep red" states including Texas, Kentucky and Georgia.