Just a thought on this: the fact that "the US and other countries" is mentioned so specifically doesn't necessarily have something to do with "discount rate", but could refer to the country have a Federal Reserve Bank or not.
Thank you very much, MM and Vince. Well, I think I agree with Vince, because every country must have a national bank (which is the Federal Reserve Bank in the case of the US and some countries). The UK (and others) may not have that FED, but they still must have a national bank, which decides the discount rate at which it lends money to commercial banks.