About three dozen flights were delayed or canceled at Logan International Airport on Friday morning as the government shutdown took its toll on Bostonians’ travel plans.

The impact appeared set to increase.

U.S. Transportation Secretary Sean Duffy said Wednesday that he was ordering a 10% reduction in flights at 40 major airports to account for an air traffic controller shortage caused by the 37-day ongoing shutdown. He said the cuts would start at 4% on Friday.

That was roughly in line with the rate of affected flights at Logan.

The airport saw 20 departing flights canceled, about 3% of its total volume, as of 9 a.m. Friday. Another 23 departures were delayed, according to data from FlightAware, a flight tracking website.

In addition, 18 flights scheduled to arrive at Logan on Friday were canceled and another 18 were delayed.

Only nine other U.S. airports saw more cancellations than Logan on Friday morning.

Other major airports hit by the reduction showed similar rates of cancellations, including Chicago O’Hare International Airport, Hartsfield–Jackson Atlanta International Airport and Denver International Airport. All saw 3% of flights canceled Friday morning.

Officials at Massport, the agency that operates Logan Airport, said they expected airlines to contact affected passengers directly.

“We urge passengers to check with their airline before coming to the airport,” the agency said.

The federal government has been shut down since Oct. 1 due to a funding dispute in Congress. Among the main sticking points is Democrats’ insistence that Republicans extend expiring healthcare subsidies that prevent sharp increases in many Americans’ medical expenses.

The shutdown is now the longest in the country’s history.

It has left about 13,000 air traffic controllers and 50,000 Transportation Security Administration officers working without pay for over a month, leading to staffing shortages, according to the Federal Aviation Administration.

“Our federal partners have continued to come to work admirably under challenging circumstances, and we remain in close communication with them, as well as with our airline partners, to minimize disruptions and keep passengers informed,” Massport said Thursday.

Delays at Logan Airport during the shutdown have been mainly due to weather conditions or ongoing construction on one of the runways, which is expected to continue through mid-November.