Until 1974 the English of translation of 'un milliard' would have been one thousand million (otherwise known in English as 'a milliard'), an English billion being one million million. The Americans being more inclined to exaggeration used Billion to mean 1,000 million, this has now been generally accepted throughout the world. see https://en.wikipedia.org/wiki/Billion for more background
In France, 1 milliard has 9 zeros -
1 000 000 000
which I believe is the equivalent to a UK billion, nowadays.
See the article I found which reiterates this -
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