BBC: President George W Bush has promised Americans their government is working "aggressively" to steady the economy.
Speaking from the White House, Mr Bush said recent market turmoil was being driven by "uncertainty and fear".
He spoke as world markets tumbled amid rising fears of a global recession, despite interest rate cuts and huge cash injections by central banks.
He also defended a recent $700bn (£410bn) rescue plan for Wall Street, saying that it was big enough.
Mr Bush said the bail-out package he signed into law a week ago would "take time to have its full impact".
Offering no new remedies, he said: "We are a prosperous nation with immense resources and a wide range of tools at our disposal. We are using these tools aggressively."
Acknowledging mounting worry among people about their retirement and investment accounts, he pledged: "Fellow citizens: We can solve this crisis, and we will."
He said the US was working "closely with our partners from around the world" to stabilise the panic-stricken markets. Bush Vows to Stabilise US Economy >>> | October 10, 2008-10-10
The Dawning of a New Dark Age (Paperback & Hardback) / Free delivery >>>
