US Commerce Secretary Penny Pritzker has warned that business is starting to suffer from the federal shutdown.
Her comments at the Asia-Pacific Economic Cooperation (Apec) came as leaders gathering for the summit voiced worries about the US situation.
Philippine President Benigno Aquino said that what happens in the US "affects us all".
On Friday, the US defence contractor Lockheed Martin said it would put 3,000 workers on unpaid leave.
The US government closed non-essential operations on Tuesday after Congress failed to agree a new budget.
And President Barack Obama cancelled a scheduled trip to Asia because of the shutdown.
"The shutdown is not good for business. It's not good for the economy," Ms Pritzker said. One consequence of the shutdown had been her department's inability to collate vital economic data.
"We're a huge source of data for American business and that is a problem... It's affecting businesses and it's affecting their ability to get data," she said.
What does shutdown mean for two million federal employees, agencies and tourist destinations?
From Monday, Lockheed will put 3,000 staff on leave, but the defence giant said this number would rise if the shutdown continued.
"I'm disappointed that we must take these actions and we continue to encourage our lawmakers to come together to pass a funding bill that will end this shutdown,'' Marillyn Hewson, Lockheed's chief executive and president, said in a statement.
"We hope that Congress and the Administration are able to resolve this situation as soon as possible," she added.
The announcement followed United Technologies' decision to temporarily lay off 2,000 employees.
The company, which makes Blackhawk helicopters, said some manufacturing had been halted because there were no government inspectors working to sign off products.
The widening impact of the shutdown sparked concern at Apec meeting in Bali on Sunday.
Mr Aquino said: "The US economy is the number one economy in the world, what happens there affects all of us.
"The world economy obviously is not in a position to withstand too much shock at this time when we are just recovering as a global economy."
Meanwhile, Chilean President Sebastian Pinera said the US had to confront its fiscal problems "in a better way than they are doing it now with shutting down the government".
Mr Obama is refusing to negotiate with the Republicans over the budget issues until they pass a temporary bill to reopen the government.
He also wants agreement to raise the $16.7 trillion US borrowing limit, to avoid the country defaulting on its debts.