WASHINGTON (REUTERS) - The Federal Aviation Administration said on Wednesday (Jan 23) that 43 flights into Newark Liberty International Airport were required to hold after drone sightings at a nearby airport on Tuesday, while nine flights were diverted.

An FAA spokesman added that the event lasted for 21 minutes.

The flights into Newark - the 11th busiest US airport - were suspended after a drone was seen flying at 3,500 feet over nearby Teterboro Airport, a small regional airport about 27km away that mostly handles corporate jets and private planes.

The issue of drones impacting commercial air traffic has taken on new urgency after Gatwick Airport, London's second busiest airport, was severely disrupted in December when drones were sighted on three consecutive days, resulting in about 1,000 flights being canceled or diverted and affecting 140,000 passengers.

The US Congress last year gave the Department of Justice and Department of Homeland Security new powers to disable or destroy threatening drones after officials raised concerns about the use of drones as potential weapons.

United Airlines, the largest carrier at Newark, said on Tuesday that the impact to its operations had been minimal.

The FAA had initially said it had reports of two drones on Tuesday evening but has since clarified to say it had two reports of one drone in northern New Jersey airspace.

Earlier this month, the US Transportation Department proposed rules that would allow drones to operate over populated areas and end a requirement for special permits for night use, long-awaited actions that are expected to help speed their commercial use.

There are nearly 1.3 million registered drones in the United States and more than 116,000 registered drone operators.

But officials say there are hundreds of thousands of additional drones that are not registered.