Speaking to the BBC’s Andrew Marr Show on Sunday morning, Tusk said it would not be automatic as there would be “formalities” to follow.
But the former Polish prime minister said: “I am very Scottish, especially after Brexit.
“Emotionally I have no doubt that everyone will be enthusiastic here in Brussels, and more generally in Europe.
“If you ask me about our emotions, you will witness I think always empathy.”
Dominic Raab, the foreign secretary, criticised Tusk for intervening in UK domestic politics.
“I think it was frankly un-European and rather irresponsible given the separatist tendencies in Spain, France and Italy,” he told the same programme.
Scotland voted by 62% to 38% to Remain in the EU at the 2016 referendum. Overall the UK backed Leave by 52% to 48%.
Nicola Sturgeon, the SNP leader and Scottish first minister, has said Scotland “will return to the heart of Europe as an independent country”
A YouGov poll published last week showed 51% support for independence – a majority for the first time in five years.
However, a majority of Scots surveyed also said they would not like to see another vote on the issue in 2020 or 2021, but most said they would like to see another referendum within the next five years.
John McDonnell, Labour’s outgoing shadow chancellor, told the BBC this morning he “desperately” did not want to see the break-up of the UK.
“I want a United Kingdom. I will always argue for that UK and I’m hoping they don’t go along that path,” he said.