Obama’s aggressive performance against Mitt Romney has restored his lead but, with just three weeks to the election, it will go down to the wire, writes Andy Sullivan

By John Riordan, New York

President Barack Obama assumed responsibility over the deadly terror attack in Libya last month that killed four Americans just hours after Secretary of State Hillary Clinton sought to shoulder the blame for any mistakes the administration made.

A fired-up President Barack Obama persistently attacked Republican challenger Mitt Romney in a critical debate, offering a striking contrast from his listless performance two weeks ago that appeared to damage his re-election prospects.