Denver International Airport has evacuated part of its main terminal to investigate a "possible security threat".
Several airlines, including British Airways and American Airlines, had ticket counters inside the area evacuated.
The security alert came in the wake of terror attacks in Brussels earlier on Tuesday.
A "suspicious package" has prompted the partial evacuation of Denver International Airport tonight, it has confirmed on Twitter.
Members of the police bomb squad are at the scene.
The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.