Obama condemns Republicans over US shutdown
1 October 2013 Last updated at 22:39 BST
National parks and museums have closed and rubbish collections stopped as some US government departments shutdown for the first time in 17 years.
The two houses of Congress failed to agree to a new budget, with Republicans insisting on repeal or delay of Mr Obama's health law.
Experts predict the lost economic output will cost $320 million a day. President Obama has accused the Republicans of holding the government to ransom.
Mark Mardell reports from Washington.