Aerosmith have cancelled several tour dates as frontman Steven Tyler is suffering from ''unexpected medical issues''.

The 69-year-old rocker posted a statement on his official Twitter page on Tuesday (26.09.17) in which he announced he is ''seeking immediate care'' for undisclosed medical reasons.

And as a result, Aerosmith have been forced to cancel the last four shows of their South American tour, as the singer has been advised against travelling and performing by medical professionals.

The message read: ''Unfortunately, due to unexpected medical issues, lead singer, Steven Tyler, is seeking immediate care and has been advised by his doctors that he cannot travel or perform at this time. Therefore, the last four shows of the South American tour will be cancelled.''

And Steven added his own statement to the message, in which he assured fans he isn't in a ''life threatening condition'', but needs to receive immediate medical care in order to ''maintain [his] future performances''.

He wrote: ''To everybody in South America....Brazil, Chile, Argentina and Mexico....I'm very sorry and feel like I've let you down..I won't be able to continue the last four shows of this tour. I flew back to the US on doctor's orders last night after the show in São Paulo.

''Please not to worry...

''I am not in a life-threatening condition, but I need to deal with this right away and get some rest and medical care immediately in order to sustain and maintain my future performances....I promise I'll be back...unfortunately, health does not wait and it's something even I can't schedule around our shows.....As they say, 'We humans make plans, and God laughs....' I love you all and will be back with you soon..... (sic)''

Following Steven's medical emergency - which has not yet been detailed - the 'I Don't Want To Miss A Thing' rockers have been forced to cancel the following shows:

Sept 27 - Curitiba, Brazil

Sept 30 - Santiago, Chile

Oct 03 - Rosario, Argentina

Oct 07 - Monterrey, Mexico