The top US general this week suggested that the Pentagon had not adequately vetted documents that allege Russia passed intelligence about US troop movements to Saddam Hussein early on during the 2003 invasion of Iraq.

On Tuesday – the same day that Condoleezza Rice, the secretary of state, asked Russia to investigate the claims – General Peter Pace, the chairman of the joint chiefs, suggested that the US had unresolved questions about the claims contained in Iraqi documents captured after the invasion.