By Nick Childs BBC Pentagon correspondent

While the United Nations awaits Baghdad's response to the latest Security Council resolution, the Pentagon's preparations for a possible military showdown with Iraq go on.

A senior defence official has told the BBC that the Pentagon is already looking at where it might station forces in Iraq in order to ensure stability in the country in the aftermath of any conflict.

Meanwhile the New York Times, quoting senior administration officials, says President George W Bush has approved a war plan for Iraq, involving up to a quarter of a million troops.

The only other country expected to contribute significant ground forces, it says, is Britain.

Pentagon officials would not confirm the report, but the figures quoted are in line with most current assessments in Washington.

So too is the suggestion that any action would probably involve a rolling start - in other words, it could begin before all the forces were in place.

But the administration insists that no decision has yet been made.

Given the UN's timetable and the current state of US military build-up, if there is to be a conflict, it is unlikely to take place before January at the earliest.