US president Joe Biden promises aid after tornado kills 25 and obliterates Mississippi town with 270km-wide path of destruction

A man talks on the phone among the wreckage in Rolling Fork, Mississippi after the series of powerful storms and at least one tornado. Photo: Will Newton/Getty

Michael Goldberg and Emily Wagster Pettus

Help began pouring into one of the poorest regions of the US after a deadly tornado tore a 270km path of destruction in Mississippi, even as furious new storms last night struck across the Deep South.