The question of Scottish independence needs to be de-coupled from Brexit, the Scottish Secretary has said three years on from the referendum.
David Mundell said the two issues have been deliberately conflated in order to push a second independence vote.
During a trade trip to South America, the Scottish Secretary called on the UK and Scottish governments to move on from "the issue that divided our country so badly" and work closer together on Brexit.
He said: "Behind the scenes, that work has been happening and I am pleased to report we are making progress. But frankly, up to now, private progress has been overshadowed by public rhetoric.
"We have been accused by the Nationalist government in Edinburgh of a 'power grab', of using our exit from the EU as an opportunity to centralise power at Westminster. That is simply not the case. Our record demonstrates our commitment to devolution.
"As a former MSP, I want to see the Scottish Parliament strengthened and that is what will happen as we leave the EU.
"I'm equally clear I want to see devolution delivered in a way that strengthens our United Kingdom - not undermines it. This, sadly, goes to the heart of the matter.
"The fact is, until the recent election in June, the Brexit debate in Scotland was deliberately conflated with the question of Scottish independence.
"Despite the passage of only three short years - and despite the decisive result - the Scottish National Party sought to use Brexit to reopen the issue that divided our country so badly.
"Their attempt was roundly rejected in the recent general election, so we now need the issues to be de-coupled for good."
Mr Mundell is in Paraguay as part of the first visit by the UK Government in more than 20 years. He is also travelling to Argentina as part of an international trade mission.
He said: "Around half of the UK's exports to Paraguay come from Scotland - mainly in the form of Scotch whisky. I understand that this has been rising steadily over the years.
"This is welcome, of course. But 20 years ago we were exporting three times as much Scotch whisky to Paraguay as we are now.
"This is something I want to see turned around in the coming years and which I see as a real Scottish opportunity. "
A spokesman for Holyrood Economy Secretary Keith Brown said: "Mr Mundell's obsession with independence and failure to understand the impact of the EU withdrawal bill is at odds with the growing consensus across Scotland that we must protect the powers of the Scottish Parliament from this legislation and that any UK-wide frameworks must be mutually agreed, not imposed by Westminster.
"We wish David Mundell every success on this trip but the best thing that could come out of it would be for the Tories to wake up to the economic damage they are causing with their disastrous approach to Brexit."