Over 6,600 flights were delayed and more than 1,900 canceled in the United States on Sunday as the government shutdown’s impact on air travel grows more significant ahead of the holidays.

Transportation Secretary Sean Duffy said Friday that air travel could take “days if not a week" to get back to normal once the government shutdown ends.

The government shutdown continues to affect American air travel, with staffing issues leading officials to slash flight schedules across the nation. The uncertainty comes ahead of what’s expected to be a very busy holiday travel period,

Follow live updates on delays, cancellations and FAA impacts as airlines cut flights amid the government shutdown.

A fter more than a month under the mounting pressure of the U.S. government shutdown, the national air-travel system now appears to be in the early stages of collapse with the FAA announcing Wednesday that it intends to reduce airline flights by 10 percent at 40 of the nation’s busiest airports.