Nicola Sturgeon has said Scotland will be at the "centre of international attention" in 2020 in her New Year message.
The First Minister highlighted the UN climate change summit in Glasgow in November as key date for the year ahead, which she said would give Scotland the chance to show it is leading by example.
Addressing the UK's scheduled exit from the EU in January, the SNP leader sought to reassure EU citizens and said the Scottish Government would work towards giving people the opportunity to "determine Scotland's future".
Sturgeon said: "As we celebrate the start of 2020 and a new decade, we look forward to a year in which Scotland will be at the centre of international attention.
"In November, the United Nations climate change summit in Glasgow will attract more than 30,000 people from around the world.
"Hopefully that summit will lead to progress in tackling the most important issue that the world faces.
"And it will give Scotland a chance to show that we are leading by example - not just by reducing our greenhouse gas emissions but by doing so in a way that helps to build a fairer, healthier and happier society."
The First Minister added: "The Glasgow summit comes near the end of what will be a historic year.
"Against the wishes of most people in Scotland, we will leave the European Union at the end of January. That will I know be a source of deep regret for many of us.
"In the year ahead the Scottish Government will do everything we can to mitigate the worst impacts of Brexit.
"We will provide support and reassurance for the EU citizens who have done us the honour of choosing to make Scotland their home.
"And we will work to ensure that people in Scotland have the chance to determine our own future - by deciding whether we wish to become an independent country.
"In all of this we will continue to ensure that Scotland remains an open, outward looking and welcoming society."
In his own New Year message, Scottish Conservative leader Jackson Carlaw spoke of his optimism the UK can move on from a "decade of division".
He said: "In the next few weeks, we will finally be leaving the European Union and delivering on the referendum we held in 2016.
"The first thing to say is to speak directly to European citizens living in Scotland and the UK.
"We may be leaving the institutions of the European Union at the end of the month but the UK and Europe remain united by our shared continent.
"This is your home and we want you to stay."
Carlaw added: "The fallout from the referendum result has created huge tensions across the country.
"I hope that, once we have left Brussels at the end of this month, those tensions will dissipate and we can come back together.
"It is time to move on from the decade of division we have just been through, and enter a new decade of delivery for all. I am optimistic that this will indeed happen."
Scottish Labour leader Richard Leonard called on the country to work to tackle poverty and climate change.
Leonard said: "New Year is a time for reflection and it's also a time for resolve.
"So we should resolve, this New Year, and in this coming decade to build a better society, one which is free from poverty and inequality. Where we don't walk by on the other side.
"A society where we recognise there is a climate emergency and take action.
"And a society where we are not putting borders and national boundaries up - but we are bringing them down.
"Let's resolve to work together to build that better society. Happy New Year."
Scottish Liberal Democrat leader Willie Rennie said Brexit and Donald Trump were among the challenges facing the UK over the next year.
In his message, Rennie said: "Around the globe, dark currents have buffeted liberal democracy.
"Boris Johnson's Brexit threatens to cut us off from our European neighbours, while Donald Trump's trade wars and Twitter tirades threaten to undo America's status as a global leader.
"Meanwhile from Hong Kong to Xinjiang, protesters and activists face brutal clampdowns.
"These are the challenges we must face up to over the next 12 months."
He added: "Closer to home there are huge challenges, too.
"From long waits for mental health treatment to the bungled roll-out of the new childcare entitlement, Liberal Democrats will highlight, debate and scrutinise the government so that everyone can rely on great public services that help them to build a brighter future."
In his message, Scottish secretary Alister Jack looked ahead to Brexit.
He said: "In one month's time, at 11pm on Friday, January 31, 2020, Scotland and the rest of the UK will be out of the EU, marking a whole new chapter in our country's history.
"I am proud to be secretary of state for Scotland as we finally achieve this.
"After years of wasteful debate and delay, the UK Government's strong majority in the Commons means, finally, we can get Brexit done.
"We will honour the result of the 2016 referendum and deliver a Brexit that works for Scottish farmers, fishermen and businesses."
Jack added: "We are stronger and more prosperous as a union of nations. Let's put the rancour and division behind us and look forward to a better future together.
"I believe 2020 will be a year of growth and opportunity, as we work to boost the prosperity of every part of the UK.
"Let's all raise a glass at midnight to a united, peaceful and prosperous Scotland in 2020."