US President Barack Obama is to call for an end to nuclear arms and efforts to stop the spread of the technology behind them, at an historic UN session. In the first security council meeting chaired by the US, Mr Obama will present a resolution seeking "a world without nuclear weapons". The meeting comes a day after Mr Obama's debut UN speech, in which he warned of a nuclear arms race. It also comes amid growing concerns over Iran's nuclear ambitions. The draft resolution reaffirms the council's commitment "to seek a safer world for all and to create the conditions...