Independence is the best way for Scotland to make a positive contribution to the world, Nicola Sturgeon said as she urged the UK Government to recognise the "right" of Scots to make that choice in the wake of Brexit.
After Theresa May began the formal process of taking the UK out of the European Union, the First Minister called for immediate recognition from Westminster of her mandate for a second independence referendum.
She used a speech at the prestigious Stanford University in the US to highlight the global role an independent Scotland could have, stressing it would remain an "open, outward-looking and inclusive" nation that would continue to welcome people from across the globe.
It would also seek to "build partnerships around the world", including with governments, businesses and universities, she said.
Her address took place a week after MSPs backed her call for talks to take place over a second independence referendum following the UK's vote to leave the EU - a decision which was not supported by voters in Scotland.
Mrs May has insisted "now is not the time" for another ballot after Scotland decided by 55% to 45% to stay part of the Union in September 2014.
Ms Sturgeon said the Brexit vote in June 2016 posed a "fundamental question for Scotland", saying the country now faces an "exit against our will from the largest trading block in the world, at the hand of a UK Government prioritising curbs on immigration above all else".
The alternative to this is independence, with its "opportunities and challenges", she said, claiming this would give Scotland "the freedom to be an equal partner with the other nations of the UK and Europe and with countries across the world".
She said: "Independence, combined with equal partnership, is the best way for us to build a fairer society at home and to make a positive contribution to the world.
"However that is something which will be debated and discussed across Scotland as we move forward. The immediate point that the UK Government must recognise is that the people of Scotland have the right to make that choice.
"I'm sure that as the people of Scotland debate independence, as in 2014, there will again be debate and disagreement about how Scotland best contributes to the wider world. But there will again be very little disagreement about whether we want to contribute.
"Our modern identity will remain open, outward-looking and inclusive. People from around the world will still be welcome to call themselves Scottish.
"And Scotland will of course continue to build partnerships around the world - including with governments, businesses and universities here in California across the United States."
The vote for Brexit had "posed a challenge" for politicians who support free trade, immigration and globalisation, the First Minister said.
But she argued the only way to "sustain support for a dynamic and open economy" is to do more to "build a fair and inclusive society".
Immigration is a major issue in both the US and Europe, contributing to the election of Donald Trump as president as well as the UK's decision to leave the EU.
While Ms Sturgeon is not meeting Mr Trump during her visit to the US, she has signed a deal with leading Democrat Jerry Brown, the governor of California, to work together to tackle climate change.
She warned that if global temperatures rise by more than 1.5C, this could spark a greater movement of people than the refugee crisis brought about by the conflict in Syria.
Scottish Labour business manager James Kelly said: "Even on a foreign trip Nicola Sturgeon can't stop campaigning for another divisive independence referendum. When Nicola Sturgeon is abroad she should be representing the interests of all the people of Scotland, not trying to build up support for a second referendum that the majority here don't want.
"Labour will never support independence. Leaving the UK would mean £15 billion worth of extra cuts to Scotland's schools and hospitals. Labour will never sign up to something that would impose such catastrophic cuts on the working families of Scotland."
Scottish Conservative chief whip John Lamont said: "Nicola Sturgeon's comments about globalisation are a near exact echo of a similar speech made by Theresa May just a few weeks ago in Davos.
"To that extent, her speech serves to demonstrate that, when politics is laid aside, there is actually huge common ground between us all on the nature of the challenge we face following Brexit.
"It's typical of Nicola Sturgeon's blinkered approach that she seeks to distort this fact in her speech.
"It is a great shame that she has chosen to use her taxpayer-funded trip to America to promote independence, and an unwanted referendum.
"She may be representing the SNP in doing so, but she does not represent mainstream Scottish opinion.
"The First Minister has dumped the day job - and not content with pushing her divisive campaign for a second referendum on independence at home, it now appears it has gone global too."
Scottish Liberal Democrat leader Willie Rennie said: "The First Minister's global grievance tour stops off in California.
"There must be a crack in Nicola Sturgeon's silicon chip for her to want to compound the shock of Brexit with a new set of barriers that could see Scotland outside of both the UK and the EU.
"If Nicola Sturgeon is serious about partnership and interdependence, she should join our campaign to give the British public the final say on any Brexit deal. Keeping the whole UK in the EU is the best way to keep Scotland in the EU."