There are more staffing cuts ahead if the US government shutdown drags on, Vice-President JD Vance has said, even as some workers at the Centers for Disease Control and Prevention (CDC) have already gotten their jobs back after receiving layoff notifications two days ago.

The Trump administration announced on Friday that seven agencies, including the CDC, had started firing over 4,000 staff.

But some of those CDC layoff notices were sent in error, a spokesman for the Department of Health and Human Services (HHS) told the BBC’s US news partner CBS News.

Out of about 1,300 CDC workers who were fired on Friday, around 700 were reinstated on Saturday, the employees’ union told CNN.

The CDC employees “who received incorrect notifications were never separated from the agency and have all been notified that they are not subject to the reduction in force”, Andrew Nixon, a spokesman for HHS, which oversees the CDC told CBS News.

But there could still be more firings ahead for federal workers, Vance told Fox News on Sunday.

“The longer this goes on, the deeper the cuts are going to be,” he said. “And to be clear, some of these cuts are going to be painful.

As the federal government shutdown approaches its second week, the layoffs expand on President Donald Trump’s ongoing mission to dramatically reduce the size of the federal workforce and slash government spending.

Under the shutdown, hundreds of thousands of federal workers have been furloughed, or sent home without pay, while essential workers like police and air traffic controllers are required to continue working, also without pay.

But the Trump administration is making a notable exception for some essential workers: US service members.

Trump directed Secretary of War Pete Hegseth to find available funds to get troops their paycheques this week – and Hegseth delivered.

The Department of Defence is taking about $8 billion from “unobligated research development testing and evaluation funds” from the previous fiscal year to pay the service members on 15 October if the funding lapse is not resolved by then, a Pentagon official told the BBC.

Democrats and Republicans remain deadlocked on resolving their funding disputes, and there is not another congressional vote that could reopen the government on the books.

Senator Mark Kelly, an Arizona Democrat, stood by the Democratic line on Sunday, saying on NBC’s Meet the Press that he won’t back down from his party’s demands to reinstate federal healthcare subsidies in the budget now, not later.

And as for the layoffs, Kelly said Republicans “don’t have to do this, they don’t have to punish people”.

Meanwhile, Republican Senator Lindsey Graham of South Carolina told NBC’s Meet the Press that he will not vote to extend the subsidies. Graham did not answer host Kristen Welker’s repeated questions about his thoughts on the recent layoffs.

Vance blamed the Democrats when speaking to Fox, saying “This is not a situation we relish, (these layoffs) are not something we’re looking forward to, but the Democrats have dealt us a pretty difficult set of cards.”

As lawmakers continue battling over the budget, more government services are feeling the effect of the shutdown. Several Smithsonian museums, research centres and the National Zoo in Washington DC closed their doors on Sunday after funding to keep them open ran out.

Representatives for the CDC, HHS, and the White House did not immediately return a request for comment from BBC.