The UK will be a standard-bearer for free trade when it leaves the European Union, Liam Fox says.
The International Trade Secretary said Brexit was a "golden opportunity" and that it was "100% wrong" to say the vote was a sign of Britain looking inwards.
The UK is unable to negotiate trade deals independently while in the EU.
Mr Fox will be negotiating new arrangements with other countries after Brexit and has already had some talks.
- Follow the latest political developments live
- Italy's PM warns UK over Brexit talks
- Kamal Ahmed on 'hard' or 'soft' Brexit
In a speech in Manchester, he said free trade had "transformed the world for the better", and that the UK had "a golden opportunity to forge a new role for ourselves in the world".
He predicted the UK would "carry the standard of free and open trade as a badge of honour" once it leaves the EU.
And he defended his recent comments that Britain was "too lazy and too fat" with businessmen preferring "golf on a Friday afternoon" to trying to boost the country's prosperity.
"What I said was as a country we have been too willing to rest upon the achievements of previous generations," he said.
"I think the figures speak for themselves."
The former GP added: "When I was a doctor my job was not to tell people what they wanted to hear, it was to tell people what they needed to hear in order to put things right."
EU 'imploding'
In an earlier interview with the Spectator magazine, Mr Fox - one of the leading campaigners for a referendum Leave vote - said the "architecture" of the EU was "beginning to peel away".
"It's going to sacrifice at least one generation of young Europeans on the altar of the single currency, and you can only rip out the social fabric from so much of Europe before it starts imploding," he said.
With the UK leaving, he said, "Germany has the potential to become the greatest ATM in global history".
He also said getting a "good future model" was more important than a speedy Brexit, but predicted the UK would have left the before the next general election.
The government has yet to set out its negotiating position, with key issues including the balance between single market access and accepting the free movement of people.
In a BBC interview, Italy's prime minister said it would be "impossible" for Brexit talks to result in a deal that gives Britons more rights than others outside the EU.
Matteo Renzi warned that leaving the EU would be a "very difficult process" - but the problems could be solved only after the UK began the exit procedure.