Chancellor Gordon Brown has announced an extra £1.25bn ($2bn) of funding to help pay for the war on Iraq.
He told the House of Commons that the new amount would take the Ministry of Defence's (MOD) special reserves for the war to a total of £3bn.
He said the money would be drawn by the MOD as necessary for action in Iraq.
"I think the whole House will want to make clear our gratitude to our armed forces, our determination to ensure they are fully supported and will want to send our condolences to the families of the 22 British servicemen who have lost their lives."
He also said he was making a further £120m available to the Department for International Development for humanitarian relief in Iraq.
One month war
Before the war began Mr Brown said the UK would "pay what it takes" to tackle Saddam Hussein's weapons of mass destruction.
The UK's war allocation is dwarfed by the figures being talked about by the United States whose fighting force is considerably bigger.
On Tuesday President Bush sent Congress a request for $74.7bn to pay for the first six months of the war.
He also asked for the freedom to spend as much of the money as he wished due to the "fluid" nature of the war.
The sum requested by Mr Bush was based on the conflict itself lasting for 30 days.