Blake Lively appeared horrified as she reacted to the foiled terrorist plot at best friend Taylor Swift’s Eras Tour in Vienna, Austria.

When asked about the planned attack at the London premiere of “It Ends With Us” last week, the actress told Access Hollywood, “Oh my gosh. I mean, how terrifying.”

Lively, 36, added, “But thank goodness that they are completely on top of that.”

Blake Lively reacted to the terrorist attack planned for bestie Taylor Swift’s Eras Tour in Vienna.

The actress told Access Hollywood, “Oh my gosh. I mean, how terrifying.”

On Wednesday, all three of Swift’s sold-out shows at Ernst Happel Stadium were canceled after local authorities confirmed a terrorist threat.

Three teenage men, who pledged allegiance to ISIS, were arrested in connection to an attack planned for one of the 14-time Grammy winner’s concerts in Vienna.

The suspects, who are ages 17 to 19, “wanted to carry out an attack in the area outside the stadium, killing as many people as possible,” said Omar Haijawi-Pirchner, head of the Directorate of State Security and Intelligence.

“But thank goodness that they are completely on top of that,” she added.

Swift’s three sold-out shows at Ernst Happel Stadium in Vienna were canceled when local authorities confirmed the terrorist threat.

Event organizers expected 65,000 concert attendees, with an additional 30,000 people outside the venue.

While the cancellation left Swifties devastated, hundreds of fans gathered by the venue after the news to sing their favorite songs by the pop hitmaker and exchange friendship bracelets.

The Vienna concertgoers were promised refunds for their tickets.

Three teenagers were arrested in connection to the terror plot.

Despite the canceled shows, Swifties gathered near the concert venue to sing the 14-time Grammy winner’s songs.

Meanwhile, Swift’s five Eras Tour concerts at Wembley Stadium in London between Aug. 15 to Aug. 20 are expected to “carry on” as planned.

The “Lover” songstress is expected to arrive in the UK capital on Aug. 14.

TMZ reported on Sunday that local authorities in London will heighten security measures by calling in private officers who specialize in counterterrorism.

Swift is expected to perform in London for five days starting on Aug. 15.

Authorities in the UK have said that security measures have been increased.

Per the outlet, there are additional concerns about the singer’s loyal fans who are known to gather outside the venues.

TMZ reported that private security officers in regular clothes and uniforms would be deployed to search for suspicious people.

London’s mayor, Sadiq Khan, appeared optimistic about the security measures, telling Sky News last week that local authorities “have a huge amount of experience in policing these events.”

The “Lover” songstress has yet to speak out about the threat in Austria.

Sources told Page Six that her boyfriend, Travis Kelce, is “very concerned

“We’re never complacent, many lessons were learned after the awful Manchester Arena attack,” Khan added, referring to the 2017 terrorist attack at an Ariana Grande concert.

While Swift has yet to speak publicly about the planned attack, her boyfriend, Travis Kelce, is worried about the pop icon.

“He’s very concerned,” a source told Page Six Thursday, revealing the Kansas City Chiefs star, who is prepping for football season, “immediately” called his girlfriend.