The CIA says the suspects in the foiled plot to attack a Taylor Swift concert in Vienna wanted to kill "a huge number" of people at the event.

The intelligence provided by the agency to Austrian authorities allowed them to disrupt the plot and save "hundreds of lives" , CIA's deputy director David Cohen said on Wednesday.

Mr Cohen highlighted that there were "tens of thousands of people at this concert, I am sure many Americans". He added that the suspects' plans were "advanced".

Three male teenage suspects were arrested in connection with the foiled attacks, allegedly inspired by the Islamic State group.

Speaking at an annual intelligence summit outside Washington, DC, Mr Cohen said the day of the arrests was a "good day for Langley", referring to the CIA headquarters. "And not just for Swifties in the office."

“The Austrians were able to make those arrests because the agency and our partners in the intelligence community provided them information about what this ISIS-connected group was planning to do," Mr Cohen said.

He did not disclose how his agency had learned about the plot.

Some 200,000 people had been expected to attend one of Swift's three Vienna concerts, part of the European swing of her multi-continent Eras tour.

On 7 August, the day before the first show, concert organisers announced the shows would be scrapped after a warning about a "planned terrorist attack" from government officials.

Earlier that day, Austrian authorities arrested two of the suspects. The third was arrested two days later.

Authorities said the main suspect, a 19-year-old Austrian citizen, had pledged allegiance to the Islamic State and had focused on the Eras tour as a target.

He hoped to “kill as many people as possible", authorities said.

Last week, for the first time, Swift commented publicly on the planned attack, writing on Instagram that having to cancel the Vienna shows was "devastating".

"The reason for the cancellations filled me with a new sense of fear, and a tremendous amount of guilt because so many people had planned on coming to those shows," she wrote. "But I was also so grateful to the authorities because thanks to them, we were grieving concerts and not lives."

Swift performed eight concerts at Wembley this summer, overtaking a record for any solo singer, which was previously set by Michael Jackson in 1988.

Her next show as part of The Eras Tour is scheduled for 18 October in Miami, Florida.