Aust sub decision 'rational': EU diplomat

European Union foreign policy chief Josep Borrell says Australia's decision to ditch a submarine procurement contract with France that triggered a transatlantic row was "rational".

"Australia decided to strengthen military and military-industrial ties with those who could offer it the best protection," he said in an event in Madrid on Friday.

The transatlantic row was triggered last month by the United States' secret negotiation of a military pact, known as AUKUS, with Australia and Britain to counter China, that excluded France.

Under the AUKUS agreement Canberra has abandoned a $A90 billion deal for France to build diesel-electric submarines for Australia, instead opting to acquire nuclear-powered submarines with the help of the US and the UK.