Obama is speaking in the Rose Garden on the first day of the government shutdown. He says the longer the shutdown continues, the worse the impact will be.
The president says Republicans should not be able to hold the entire economy "hostage." He is urging them to reopen the government quickly and allow furloughed federal employees to go back to work.
The government shut down because Congress did not pass a funding bill ahead of Monday's midnight deadline for the end of the 2013 fiscal year.
Earlier Tuesday, Obama sent federal workers a letter lamenting that they had become "punching bags" in Washington's partisan fiscal fights. About 800,000 federal workers are being forced off the job.
Obama says that if the shutdown continues, it will make it more difficult to recruit talented people for government jobs.