US shutdown: 'Mission critical' that debt ceiling resolved
3 October 2013 Last updated at 16:42 BST
IMF managing director Christine Lagarde says it is "mission critical" that the US agrees a new debt ceiling.
The US is up to its borrowing limit and will run out of money without agreement to lift it.
In a speech looking ahead to a decade of challenges for the world economy, Ms Lagarde said that the US government needed to fix its finances for the long term.