American Airlines grounds all US flights following 'unspecified technical issue'

American Airlines has grounded all of its US flights on one of the busiest days of the year.

The largest airline in the country has been forced to halt all of its flights across the nation today (December 24) because of a technical issue.

American Airlines said in a statement shared to social media: "An estimated timeframe has not been provided, but they're trying to fix it in the shortest possible time."

Elsewhere, the Federal Aviation Agency (FAA) said, as per Sky News: "American Airlines is reporting a technical issue and has requested a nationwide ground stop.

"Please contact American Airlines for more information."

Shortly after the news of the flights being grounded, it was confirmed that the nationwide groundstop was lifted as the system that crashed resumed its usual services, BBC News reported.

The grounding of its flights marks a second technical issue American Airlines has had in recent months. Back in July, the airline - along with others - was forced to ground its flights because of an IT crash.

It's thought the debacle was down to a huge Microsoft Azure cloud outage on the day in question.

American Airlines briefly had to ground all of its US flights on Christmas Eve (DANIEL SLIM/AFP via Getty Images)

Microsoft said at the time: "We are aware of this issue and have engaged multiple teams.

"We’ve determined the underlying cause. A backend cluster management workflow deployed a configuration change causing backend access to be blocked between a subset of Azure Storage clusters and compute resources in the Central US region."

The issue also affected parts of the UK and Australia.