From the Bush Administration,

Nick Berg was never in US custody. The US military was trying to pull him out. Even now, we are trying our best to protect the lives of Americans, may they be citizens or the military.

Egyptian experts were first to verify the voice on the grisly tape as that of Osama bin Laden's closest associate Abu Musab al-Zarqawi as early as May 12. 

We knew he (Hussein) had terrorist ties. The person responsible for the Berg death, Zarqawi, was in and out of Baghdad prior to our arrival, for example. 

We shall get Abu Musab al-Zarqawi, and the whole Al Queda network, for beheading American Nicholas Berg. As of today, Abu Musab al-Zarqawi is currently more important than Osama bin Laden. 

								We feel your lost, and 
								may god protect us all. 
								Bush Administration