The UK must remain a "beacon" for liberal, democratic values in the wake of the vote to leave the EU, Ruth Davidson has said.
In a speech to an audience of foreign diplomats in London, the Scottish Conservative leader will say that the country will be outward looking and "will not turn in on ourselves".
Ms Davidson backed a Remain vote in June's referendum along with the vast majority of colleagues in the Scottish Conservatives.
She took part in one of the final live TV Brexit debates and clashed with high profile Leave campaigner Boris Johnson, now Foreign Secretary.
In her speech at the European Council on Foreign Relations, Ms Davidson is expected to say: "I know there are many diplomats here today from our friends and allies around the world.
"I want to repeat the message that many others have given in the weeks since the referendum result - from both sides of the referendum divide.
"That, while we are leaving the European Union, we are not leaving Europe, and we will not turn in on ourselves.
"I fought for Britain to stay together in the Scottish referendum two years ago. I did so not just because of the bottom line but because I believe the United Kingdom is a force for good.
"Now that we are leaving the European Union, more than ever, we must prove to you that we remain that same outward facing nation which wants to play our full part...which seeks to be a beacon for the values we share - of the rule of law, freedom and solidarity with one another.
"The structures behind our relationship will change over the coming years. I am confident that the nature of our friendship will not."
A spokesman for First Minister Nicola Sturgeon said: "The evidence is mounting by the day of the potentially huge damage Brexit threatens to jobs, investment and Scotland's economy.
"It is Ruth Davidson and her Tory colleagues who have created the problem but who also appear utterly clueless about how to fix it.
"As a start, perhaps Ms Davidson can answer the simple question that her boss the Prime Minister was unable to answer last week: does she believe the UK should continue in the single market - yes or no?
"The First Minister has made clear that we will be exploring all possible options to protect Scotland's future in Europe - and it is absolutely right that independence should be one of those options."