- More than 6,000 flights were canceled and delayed on Friday and Saturday.
- Cancellations come after 1,700 flights were axed and 8,800 delayed on Thursday.
- Travelers are facing uncertainty over their Juneteenth and Independence Day holiday plans.
Airlines are continuing to cancel thousands of flights this weekend as passengers travel for the Juneteenth holiday on Monday.
Labor shortages, the global fallout from war in Ukraine as well as weather disruptions are all factors in the cancellations.
More than 6,000 flights were canceled or delayed across Friday and Saturday, according to data from flight tracker Flight Aware.
The cancellations come after 1,700 flights were scrapped and 8,800 delays on Thursday within or two and from the US, Flight Aware data shows.
A further 781 flights scheduled to operate on Sunday have also been axed, with American Airlines, Delta, Spring Airlines and China Eastern among the carriers with the most cancellations.
"Air travelers should be able to expect reliable service as demand returns to levels not seen since before the pandemic," the transportation secretary, Pete Buttigieg, tweeted on Friday.
Many airlines have regularly been axing flights in recent months amid an ongoing labor shortage.
More than 2,500 flights were canceled over the Memorial Day weekend, disrupting travel plans for hundreds of thousands of people.
After the Memorial Day weekend disruption, two senators urged Buttigieg to hold the airlines accountable in an open letter on June 2.
The letter, signed by Democrat senators Richard Blumenthal and Edward Markey, said they understood that airlines were taking measures to recruit more staff. However, they said "thousands of passengers are still turning up at airports only to have their flights canceled at the last minute".
Travelers now face further uncertainty over their Independence Day holiday plans.
On Thursday Delta pilots wrote an open letter indicating they were just as frustrated as passengers by the disruption and said they were "flying a record amount of overtime".
In May, Delta announced that it was canceling about 100 flights a day in July and August to minimize disruption.
Other airlines including American, which has suspended about 100 regional routes due to a lack of pilots, have been forced to follow suit.