Brazilian president Jair Bolsonaro has been admitted to a hospital to determine what is causing hiccups that have lasted for days, according to a statement from hi office.

Mr Bolsonaro was at the Armed Forces Hospital in Brasilia and was “feeling well,” according to the statement. He was to be under observation for 24 to 48 hours, either at the hospital or at home.

The president has appeared to struggle with speaking on various occasions in recent weeks and said that he suffers from recurring hiccups.

“I apologise to everyone who is listening to me, because I’ve been hiccupping for five days now,” Mr Bolsonaro said in an interview with Radio Guaiba on July 7.

He suggested that some medication prescribed after dental surgery might be the cause.

“I have the hiccups 24 hours a day.”

The following day, during his weekly Facebook Live session, Mr Bolsonaro apologised again for not being able to express himself well due to week-long hiccups.

The president was seriously injured on the campaign train in 2018, when he was stabbed in the abdomen, suffering intestinal damage and serious internal bleeding.

He has has gone through several surgeries since, some unrelated to the attack.

Mr Bolsonaro has been under growing pressure from a congressional inquiry into his administration’s handling of the pandemic and alleged corruption in the acquisition of vaccines against Covid-19, and recent polls have indicated that he could lose in the 2022 election.

On Tuesday night, in a 20-minute encounter with the president in Brasilia, supporters repeatedly asked him to look after his health.