The Prime Minister travelled north of the border for the first time since the general election in December to meet businesses hit by the coronavirus pandemic.
Mr Johnson said the “sheer might” of the UK had been shown during the outbreak, with almost 900,000 workers in Scotland benefiting from Government assistance.
He said: “The last six months have shown exactly why the historic and heartfelt bond that ties the four nations of our country together is so important and the sheer might of our union has been proven once again.”
But Ms Sturgeon tweeted: “I welcome the PM to Scotland today. One of the key arguments for independence is the ability of Scotland to take our own decisions, rather than having our future decided by politicians we didn’t vote for, taking us down a path we haven’t chosen. His presence highlights that.”
The visit comes amid a surge in support for Scottish independence, with surveys reporting 54 per cent would back it.