Canada.
Although the Canadian government has not publicly announced that they are testing a state-backed cryptocurrency, the Canadian central has expressed interest in potentially issuing a digital asset controlled by the Central Bank which acts as a digital version of the Canadian Dollar. In July 2018, the Canadian Central Bank conducted a study called the Central Bank Digital Currency and Monetary Policy which highlighted the potential benefits of a state-backed digital asset.
Canada came up with Mintchip and abandoned the idea in 2014 or so. I wonder what's changed.
If any of these come about the case for crypto will be several times stronger. The grip they'll have over your money will be far, far tighter with a governmentcoin than the current lash up of a system.