Ash Carter
Defence secretary Ash Carter has announced women can serve on the battlefield Getty

Women in the US army will serve on the battlefield for the first time after Defence Secretary Ash Carter smashed the military's glass ceiling and announced they could fight alongside male soldiers from April 2016.

Carter is giving the armed services until 1 January 2016 to submit plans to make the historic change and must start to be implemented by April, according to the Associated Press. Carter said in a statement: "We cannot afford to cut ourselves off from half the country's talent and skills."

According to a defence source, the reform means female recruits will be able to join the prestigious Army Delta units and Navy Seals. It comes after Joint Chiefs of Staff chairman General Joseph Dunford said the Marine Corps should be allowed to exclude women from certain front-line combat jobs because studies showed they were not as capable as all-male units.

Speaking in October, in response to a question from a Marine in Sicily, Carter indicated his support for the change, saying it would be "crazy" to not allow women to fight. He said: "You have to recruit from the American population. Half the American population is female. So I'd be crazy not to be, so to speak, fishing in that pond for qualified service members."