Not a very structured interview process - it is dictated by the availability of the President. He is out of the country months at a time so if you are not available when he is in DC, you will need to wait as he is the one to make the final call.
After meeting with the President, you will be handed off to the US staff to sit down and speak more candidly about the company culture and expectations. I suggest taking advantage of this time to get to understand their experiences and to learn about the client sectors they are currently managing.