Rishi Sunak has encouraged people to be "comfortable failing" when they start businesses during a conversation with billionaire Elon Musk.
The pair spent close to an hour talking at an event in central London where journalists were invited but not allowed to ask questions. Business leaders were given a chance to put questions to the duo.
They spoke about how to encourage people to start their own businesses. They also ranged onto topics like how to stop killer robots.
Mr Sunak spoke about how, as prime minister, his job was to make the country start-up friendly, hinting at reforms that may be coming in the autumn statement - including on pensions.
The prime minister said Chancellor Jeremy Hunt has got a "bunch of incredible reforms to unlock capital from all the people who have it and deploy it into growth equity" - but they're a work in progress.
Mr Sunak went on to say another challenge for encouraging start-ups was "how do you transpose that culture from places like Silicon Valley across the world where people are unafraid to give up the security of a regular pay cheque to go and start something, and be comfortable with failure."
He added: "You've got to be comfortable failing, and knowing that's just part of the process. That's a tricky cultural thing to do overnight, but it's an important part of I think creating that kind of environment."
Mr Musk - who is the world's richest man - told Mr Sunak - who is estimated to be worth hundreds of millions of pounds - that someone's first start-up failing "shouldn't be a catastrophic, career-ending thing".
The business leader said that, since starting a company is "high risk, high reward", that people need incentives.
Mr Sunak said that he agrees, and said that relative to many European countries and California, the UK has much lower capital gains tax.
The event, which came after Mr Sunak's two-day AI safety conference near Milton Keynes, saw the pair also speak about killer robots and other aspects of technology.
Mr Musk described artificial intelligence as "a magic genie" that grants you limitless wishes.
On robots, Mr Musk emphasised the need to have an off-switch - what some might call a kill-switch - for humanoid cyborgs.
"A humanoid robot can basically chase you anywhere," he said, adding, "it's something we should be quite concerned about. If a robot can follow you anywhere, what if they get a software update one day, and they're not so friendly any more?"
Mr Sunak said "we've all watched" movies about robots that end with the machines being switched off.
Labour's shadow paymaster general Jonathan Ashworth said: "How out of touch is Rishi Sunak? After 13 years of the Tories, the public are enduring the worst cost of living crisis in memory and he is spending his time telling Elon Musk that he wishes they would give up their jobs and be ready to fail.
"He hasn't got a clue."