Sudanese payments blocked

We are hearing repeated stories of British banks refusing to accept payments from Sudan for legitimate British exports. One report even went to far as to tell of a Bank requiring a written undertaking from their customer that he would have no further dealings with Sudan. Lack of such undertaking would result in the closure of the account. Needless to say, no explanations are forthcoming. It is thought that they are kow-towing to USA who have an embargo on trade with Sudan.

Does anyone know of pressures being brought by USA on our banks?

Does anyone have any experience of receiving money from Sudan, so that business can continue?