Zayn Malik has thanked fans for their support after a severe anxiety attack forced him to cancel his first live U.K. performance.

The former One Direction singer had been billed to hit the stage at the Capital FM Summertime Ball at London's Wembley Stadium on Saturday night (11Jun16), but he disappointed gig-goers by pulling out at late notice.

As festival organizers broke the news to fans at the venue, Zayn took to social media to try and explain himself in a candid, lengthy note.

"I flew into the UK last night to appear in my home country in front of my family, friends and most importantly, my UK fans," he wrote. "Unfortunately, my anxiety that has haunted me throughout the last few months around live performances has gotten the better of me...with the magnitude of the event, I have suffered the worst anxiety of my career."

Zayn went on to apologize for letting his fans down after they had patiently waited to see him perform, but promised to make it up to them as soon as he could.

"I know those who suffer anxiety will understand and I hope those who don't can empathize with my situation," he added.

According to concertgoers, the boos Zayn received following the announcement were "deafening" and many ticketholders left before the last act of the night, Tinie Tempah, took to the stage to close the show, which had also featured sets by Craig David, Little Mix, Ariana Grande, and Nick Jonas.

Despite the crowd disappointment, other fans took to Twitter.com to share sympathetic messages with the star, including his on/off girlfriend Gigi Hadid, who praised her beau for his strength during the trying time.

"Z - I've seen the battles you go through and the way you fight to get to a place that allows you to get up there for your fans," she wrote. "Your bravery in those times makes me proud, but your honesty last night proved what you’re all about, being real. Human recognizes human. You made the best of the situation and have given your fans an opportunity to understand you better as a performer.

"Those who can find compassion are now the ones that deserve to watch you continue to grow. We are all here to support you and make each experience easier. Your talent and good heart will never lead you wrong."

"Love you and so proud of you always. xG," she concluded.

The ex-boyband member returned to Twitter.com early on Sunday (12Jun16) to express his gratitude for Gigi and his fans for their tireless support.

"Thank you for your kind messages of support," he wrote. "It means a lot."

The concert cancellation occurred a day after Zayn was spotted in public with Gigi in New York City for the first time since splitting at the start of the month (Jun16). The young stars were said to have called time on their romance, which began in November (15), on 2 June (16), but sources claimed they reconciled days later, and the pair proved it was back on on Friday (10Jun16) as Gigi and Zayn were photographed leaving the model's Big Apple apartment.