The International Monetary Fund is considering scaling back how much money it needs to rebuild its war chest for handling financial crises, and it may not strike a deal with members next week, the IMF head said on Thursday.

"We need to cautiously reassess, and yes we are reassessing to a lower number in terms of risk, which will bring me to probably reassess a lower number of additional resources needed. I am not fixated on any particular number yet," IMF managing director Christine Lagarde said.

The IMF last year had asked its membership for up to $600 billion in extra resources when the euro zone sovereign debt crisis was at its height. Since then financial markets have calmed and investor confidence increased. IMF resources are on the agenda for its spring meetings next weekend.

Lagarde said she would like as much money as feasible.

"We will see how we end up, first of all at the spring meeting, and further on because clearly it is a path to embark upon and that probably will take a little bit of time. But I hope to make some real progress at the time of the spring meeting," Lagarde said after delivering a speech at the Broookings Insitution.

(Reporting by Lesley Wroughton and Glenn Somerville; Editing by Chizu Nomiyama)