More than 700 flights nationwide have been canceled Saturday as the Federal Aviation Administration continues limiting flight capacity at 40 major U.S. airports amid the government shutdown.

As of 6 a.m. ET on Saturday, 754 flights have already been canceled nationwide and the total could eclipse Friday’s toll of 1,024 cancellations.

However, despite more than 1,000 flights being canceled on Friday, major delays at airports across the country continue to persist due to staffing issues in air traffic controller towers and centers.

If the government shutdown continues, more air travel reductions could be on the way, Transportation Secretary Sean Duffy said in an interview on ABC News Live on Friday.

“My hope is that this government shutdown will end soon and we can get back in the business of letting Americans travel,” Duffy said in the interview.

It is possible the Department of Transportation may ask airlines to cancel more than 10% of their flights if controllers keep calling out in higher numbers, Duffy told ABC News.

Duffy said the FAA has asked private jets to avoid flying at the 40 airports impacted by the flight reductions, though they are currently not prohibited from flying there. He said private jet companies have been cooperative and are choosing alternate airports to help alleviate the pressure at those airports.

The cancellations are the latest — and perhaps biggest — disruption to air travel since the government shutdown began more than a month ago.

The FAA decided not to cut any international flights as it would be a violation of international agreements with the countries, according to Duffy.

“We have international agreements that we abide by, and because of those international agreements, I’m not going to impact those international flights. And because if I do, what will happen is we have other countries that are waiting to have a breach of those contracts from the US so they can cut down American flights, and then that would have a very long lasting impact on our ability to to to send travelers from the U.S. to those partners that have the agreements,” Duffy said.