Transportation Secretary Pete Buttigieg on Wednesday said that there have been “more mistakes than usual” in U.S. air travel recently after dozens of close calls, pressing the air travel sector to help address the situation.

“U.S. aviation remains an exceptionally safe mode of travel — whether you compare it to other modes, whether you compare it to other places or whether you compare it to other times in our own history. We take nothing for granted and we are particularly concerned because we have seen an uptick in serious close calls that we must address together,” Buttigieg said at the Federal Aviation Administration (FAA) safety summit.

“Initial information suggests that more mistakes than usual are happening across the system, on runways, at gates while planes are pushing back, in control towers, and on flight decks,” the secretary added.

The FAA convened the summit after a series of close calls among planes. Buttigieg told ABC News recently that the U.S. is on track to have more than 20 close calls with aircraft this year. 

The FAA and National Transportation Safety Board (NTSB) are investigating a close call in Florida last month, when a flight was cleared to take off on the same runway where another was cleared to land and another incident in Texas last month when a cargo plane flew over the top of a commercial flight taking off.  

The FAA in January had a systems shutdown that briefly halted all flights nationwide due to a computer outage. 

Buttigieg on Wednesday called on leaders at the summit to consider questions in the next few weeks to help address the situation, such as what is the data showing and what is missing, and what are the root causes of the problems.

“As we look at the recent incidents of the last year or so and as NTSB and FAA continue to investigate, we can’t wait for the next catastrophic event to seek the warning signs of today. Fully determine the contributing factors and swiftly address them,” Buttigieg said.

He also asked leaders to question what’s working well, what are the new steps that need to be taken and, beyond aviation, can they learn from other high-stakes industries with workforces that have also gone through dramatic changes due to the COVID-19 pandemic.

Buttigieg said addressing the close calls is a key priority of the Biden administration and listed some steps already in place that could help the situation, such as the rollout of taxi way arrival prediction features and modernizing airport infrastructure.

“We’re not going to rest easy with past success,” he added.

Buttigieg has been the face of the administration’s response to the issues with air travel with President Biden’s nominee to lead the FAA still being considered in Congress.

The Biden administration told lawmakers earlier this month that the nominee, Phil Washington, doesn’t need a waiver to be confirmed after Republicans insisted he did. Washington, who has been CEO of Denver International Airport since 2021, is a retired military officer, and the FAA administrator must be a civilian.