GREEN BAY, Wis. — The United States Postal Service says it’s facing unprecedented challenges this holiday season that are causing deliveries to be delayed.

The country’s mail agency says deliveries are backlogged as distribution centers throughout Wisconsin are dealing with historic package volume and temporary shortages in workers because of the COVID-19 pandemic.

USPS communications specialist Bob Sheehan shared a state with Spectrum News Monday that, in part, read:

“While every year the Postal Service carefully plans for peak holiday season, a historic record of holiday volume compounded by a temporary employee shortage due to the COVID-19 surge, and capacity challenges with airlifts and trucking for moving this historic volume of mail are leading to temporary delays. These challenges are being felt by shippers across the board.

We continue to flex our network including making sure the right equipment is available to sort, process and deliver a historic volume of mail and packages this holiday season.”

The USPS is working to has expanded its Sunday delivery to locations with high package volumes. USPS already delivers packages on Sundays in most major cities. Mail carriers will also deliver packages for an additional fee on Christmas Day in select locations.