The US authorities may completely close the country's airspace due to the threat to air safety, US Transportation Secretary Sean Duffy announced.
"If we thought it wasn't safe, we would have closed all the airspace," he told CNBC. According to a US official, the ongoing shutdown carries an element of risk, and US authorities are prepared to suspend flights if necessary.
On Sunday, Duffy warned of flight cancellations and delays across the country due to a shortage of air traffic controllers due to the US government shutdown.
