Several flights to and from Missoula International Airport were canceled on Sunday and Monday as airlines continue to adjust their schedules to meet dwindling demand and a national travel advisory enters its second week.

As the Senate continues to debate a stimulus package, Sen. Jon Tester is urging his colleagues to ensure local airports are included in the legislation.

“Our airlines play a critical role in the U.S. economy, and Montana’s airline industry relies on small regional airports that connect this country together, and which have seen a significant drop in traffic over the last week,” Tester said Monday.

“While the president considers a boost for air carriers, I’m urging him to support a plan to help our local airports that employ hundreds of workers, help drive our state’s economy and keep us connected.”

Last week, Missoula International Airport said passenger numbers were roughly half of what's normal for early spring, and it was bracing for a potential reduction in service.

On Sunday and Monday, several flights from regional hubs into Missoula were delayed or canceled, including United Airlines from Denver and an Alaska Airlines flight from Portland. United Airlines canceled 173 flights, or 41% of its incoming and outgoing flights to Denver International Airport, the Denver Post reported on Monday.

Missoula Airport officials weren't immediately available Monday for comment on the cancellations or delays, though they're not alone in their concerns over the long-term impacts.

According to industry association estimates, U.S. airports are on track to lose nearly $14 billion in operating revenue in 2020. Tester said airports are also facing uncertainties about their ability to complete projects and pay debt during the pandemic, all while facing greater demands for increased services under normal times.

He and other members of the Senate are urging the Trump administration to ensure that airports across the country get the funding and resources they need to deal with the COVID-19 crisis.

“Airports play a key role in our local and regional economies and ensure our constituents have access to the national aviation system,” Tester wrote in a letter to the president.

“As your administration considers proposals to help our nation’s airlines respond to this public health crisis, we urge you to ensure sufficient funding is also available to meet the needs of our nation’s airports.”