Nicola Sturgeon has said she feels "deeply frustrated and depressed" by the prospect of a no-deal Brexit while the UK is still dealing with the Covid-19 pandemic.
The First Minister said coronavirus should have "100% of our time and energy".
It follows comments from Boris Johnson that the UK should prepare to move on to Australian-style rules when the Brexit transition period ends.
The Prime Minister said discussions in Brussels have made it clear the EU is not going to offer the Canada-style arrangement he has sought.
Ms Sturgeon was asked about the risks of a no-deal exit from the EU at the daily coronavirus briefing on Friday.
She said: "I feel deeply frustrated and depressed at the prospect of no-deal at the end of the transition period in December.
"That said, being realistic, any deal that is struck right now is going to be such a bare minimum deal that there is going to be disruption.
"I find it very, very frustrating that at a time when all of us should be giving – and I am seeking to do as much as I possibly can – 100% of our time and focus and energy to Covid."
The First Minister said she is confident the Scottish Government can cope with the implications of a no-deal Brexit, which she said could be "huge".
She added: "Make no mistake, resources are finite and every civil servant or every hour of my time that has to be spent right now thinking about the implications of a no-deal Brexit or a bare minimum deal Brexit is a civil servant or an hour of my time that is not focused, as it should be, on trying to steer the country through the Covid pandemic."
Ms Sturgeon said planning for "constitutional matters" she supports have been put on hold by coronavirus but the UK Government has not done the same on Brexit.