Washington, Jan 18 (IANS): US Secretary of State Antony Blinken had to change planes while returning to Washington from Davos after his Boeing 737 aircraft had a "critical failure", the media reported.

Blinken was in Davos this week to attend meetings on the sidelines of the World Economic Forum (WEF) in the Swiss city.

The incident occurred on Wednesday when Blinken and the traveling press boarded the modified Boeing 737 jet in Zurich, CNN reported.

According to the travelling press, the aircraft suffered the issue after boarding and they were forced to deplane.

A new, smaller aircraft was being sent for Blinken, and many in the traveling party will now be returning to Washington commercially, they added.

Addressing the media on Wednesday night, State Department spokesperson Matt Miller said the plane suffered a mechanical issue.

He however, referred further questions to the US Air Force, reports CNN.

This latest development comes as Boeing is facing a number of issues on its aircraft.

On January 5, an Alaska Airlines jet had a door plug blow out shortly after takeoff when the plane was at 16,000 feet, leaving a gaping hole in the side of the jet.

The Alaska Air plane is a newer version of the 737 than the one that Blinken had been set to ride on, which is an older model modified for use by the military.

But the newer version, the 737 Max, has had a series of serious problems long before the Alaska Air incident this month.

Two crashes of the 737 Max, in 2018 in Indonesia and 2019 in Ethopia, killed all 346 people on board the flights, and led to a 20-month grounding of the jet.