He said the bloc's senior figures "serially" talk about Northern Ireland "as if it were somehow a different country from the UK".
The UK and EU are currently at loggerheads over the implementation of post-Brexit arrangements for Northern Ireland - known as the Northern Ireland Protocol - ahead of the end of a "grace period" for some border checks at the end of this month.
The row has threatened to overshadow the UK's hosting of the G7 summit in Carbis Bay, Cornwall, this weekend - during which Prime Minister Boris Johnson has claimed some in the EU needed to "get into their heads" that the UK is a single country.
The prime minister's ire is reported to have been raised during his bilateral talks with French President Emmanuel Macron on Saturday morning.
Johnson is said to have attempted to explain his frustration with the protocol by asking what Macron would do if sausages from Toulouse could not be moved to Paris.
The French president was claimed to have responded by arguing the comparison did not work because Paris and Toulouse were both parts of the same country, thereby suggesting Northern Ireland is not within the UK.
Asked by Sky News at the G7 summit if those reports were true, Raab said "as a matter of diplomatic professionalism" he would not "spill the beans".
HJ/PR