WASHINGTON (Reuters) - United States President Barack Obama is willing to sign a "clean" Bill to raise the US debt ceiling - one that does not include policy demands - but it is not yet clear what House Republicans are proposing, White House spokesman Jay Carney told reporters on Thursday.

"The President is happy that cooler heads at least seem to be prevailing in the House," Mr Carney said, responding to news on Thursday that House Republicans are working on a short-term extension of the debt ceiling.

"We haven't seen a Bill yet," he added.