United States Treasury Secretary Henry Paulson says that the current economic conditions were "not acceptable to the American people".

But he remained optimistic that the long term fundamentals are strong in his country.

Paulson made the remarks after meeting with British Chancellor of the Exchequer Alistair Darling on Thursday.

"I think the steps that our Federal Reserve took in response to Bear Stearns, opening their discount window to the investment banks was a very strong statement about the emphasis that's being placed on the stability and orderliness of our markets."

Banks in both Britain and the United States have suffered the impact of the global credit crunch in recent months and have needed government intervention.

US investment bank Bear Stearns was spared from near collapse in March after the Federal Reserve orchestrated its sale to JPMorgan Chase.

In Britain, mortgage lender Northern Rock was nationalized in February after worries over its future triggered the first run on a British bank since 1866.

Alistair Darling called for international cooperation to handle the situation.

"Whether it's the credit crunch which is now affecting every country in the world or the huge threat posed by very high oil prices and the inflationary effect that can have or rising food prices. These are international problems that will need countries to work together and the United States and the United Kingdom share a common interest and we have a shared commitment."

London was the final leg of Paulson's European tour, which also brought him to Russia and Germany.