Republicans in the Senate are expected to block a bill by President Barack Obama's Democrats to increase the US debt limit through 2014, Reuters reported, citing a senior congressional aide.
The aide said Democrats were prepared to try to build up support and bring up the bill again in coming days.
The bill was expected to be blocked today by a Republican procedural hurdle that takes 60 votes to clear in the 100-member chamber - Democrats control the Senate, 54-46.
The US shutdown is but a precursor to a much bigger problem - in a couple of weeks the government, shutdown or not, will run out of cash.
Landmarks across the US have closed as the Congress failed to reach a deal over the budget.