Found out about ABPS through internet search;;searching for fellowship in emergency Medicine

hello ,
 
I am a emergency physician in the UK; geting towards the  end of my training and expecting to do my fellowiship exams  of the College of Emergency Medicine, UK this autum. I would like to pursue more training and be certified with the ABPS.
Could you direct me how to gain this.
 
If  registration is exclusively for US residency programmes, are ther any options of doing any fellowship programmes in the USA. 
Do i need to do the USMLE exams for this?
 
please give me as much information as possible
 
thanks
 
Ashid Kodumayil
Registrar in Emergency Medicine
UK