The UK has signed a defence trade deal with the US which will make it easier for the two nations to work together.
Tony Blair stressed the importance of the deal with the US
The treaty, agreed by Tony Blair and President Bush, will also give the UK access to sensitive US technical data.
The PM said it was important for the two nations to co-operate because their forces were working closely together in military operations around the world.
The MoD said it would make it easier to buy equipment which might be needed at short notice in Iraq and Afghanistan.
Mr Blair said: "This will enable our two countries to share defence information, goods and services more effectively.
"Achieving this agreement has become more important than ever before.
"At a time when British and American forces continue to work closely in defence and security operations around the world, both governments believe we must continue enhancing our ability to co-operate together."
The Ministry of Defence said the agreement was far wider than the one at the end of 2006 to share technical codes which saved the Joint Strike Fighter deal.
The US satisfied demands to reveal technical details of the fighter before the UK committed to the £140bn project.
British defence chiefs were under pressure not to go ahead with to plans to buy 150 of the aircraft unless the US released details to allow the jets to be operated independently by the UK.