THE United States is bracing for the release - as early as tomorrow- of up to three million classified State Department messages sent between US embassies around the world.

The website WikiLeaks is preparing to leak the huge pile of diplomatic cables, with the release having the potential to ''destabilise global security'' and ''jeopardise lives''.

The new detail was found in an email sent by a senior US bureaucrat to two important US government committees yesterday.

It will be the third and largest release of material allegedly given to WikiLeaks by the US soldier Bradley Manning, a Middle East-based army intelligence analyst who has since been charged by US authorities.

The latest release was announced earlier this week, but it was unclear what the material would be about. An email from an assistant defence secretary, Elizabeth King, warns the US Senate and House committees on armed services of the potential dangers.