Brazil's President Jair Bolsonaro has revealed he is to undergo further abdominal surgery, his fifth since being stabbed on the campaign trail in September 2018.

"There will be another operation. It should be the last," Bolsonaro said in a pre-recorded interview broadcast late Sunday on Brazil's Record TV.

Bolsonaro was stabbed in the stomach by a suspected radical leftist during a campaign rally in September 2018, before he was elected president.

He underwent four operations on his stomach, the most recent last September.

In January, he told journalists he was suffering from a hernia and that he would undergo a health check in February.

This video grab taken from Brazil's President Jair Bolsonaro's official Twitter account in January 2019 shows the Brazilian leader speaking before undergoing surgery in a Sao Paulo hospital to remove the colostomy bag that was placed after  a knife attack
This video grab taken from Brazil's President Jair Bolsonaro's official Twitter account in January 2019 shows the Brazilian leader speaking before undergoing surgery in a Sao Paulo hospital to remove the colostomy bag that was placed after a knife attack on the campaign trail Jair Bolsonaro's official Twitter account / HO

"It's the age. I'm 64, there were four operations in which they opened up the whole abdomen. Twice, they took out everything (his intestines). It was extremely serious."

Surgeon Regis Ramos told reporters at the time that a lateral hernia caused the president "occasional discomfort."

Contacted by AFP, the president's office did not provide a likely date for the latest procedure.

The far-right leader had several health issues since assuming office. He was hospitalized on December 23 after a fall at his residence in which he later said he'd temporarily lost his memory.

He also expressed concerns about "a possible skin cancer," but a biopsy came back negative.

The interview was aired while Bolsonaro was in the United States where he signed a defense agreement and was a guest of President Donald Trump at his Mar-a-Lago resort in Florida.