Iowa's six electoral college votes have gone to Barack Obama, according to NBC News projections.
The President now leads Mitt Romney by 249 to 203, with Florida and Ohio yet to be called.
More top news
Crime figures show a sixfold increase in people reporting a rape by someone they met on a dating app or website, between 2009 and 2014
The launch was made in defiance of United Nations sanctions barring North Korea from using ballistic missile technology.
David Cameron has raised concerns after figures showed 100 babies spent time living behind bars last year.