There does seem to be a significant difference between the US approach and other countries. In the US a clearance to make an approach is issued 15 minutes or so before touchdown as the aircraft is still in descent 10,000 - 8,000ft and the aircraft takes that as you can land off the approach. In other countries an explicit landing clearance is required and is provided at 2 or 3nm prior to touchdown, if not the aircraft is expected to go around. This was highlighted in the case of an aircraft landing at DCA when the Tower controller was not responding to phone calls and did not issue a clearance but an aircraft landed anyway.