International trade secretary Liam Fox has hit out at Brexit scaremongering and promised a "new and exciting chapter" in UK-US trade relations.

Addressing the American Enterprise Institute (AEI) in Washington, DC, on Monday (24 July), Fox said a British-American working group would provide a "springboard" for a comprehensive free-trade agreement.

Mocking those who predicted economic catastrophe in the event of the UK's exit from the European Union, Fox quipped: "There are those that tell us, despite the evidence, that Brexit is going to be economically dreadful for us, that it will never work!

"Where is this dreadful economic armageddon that was supposed to happen? "

Fox added: "As we prepare to leave the EU, Britain enters a new chapter in our history. And we will do so as proud champions in the cause of global free trade, unashamedly promoting the importance of the rules-based system and helping to ensure that the proceeds of prosperity are distributed to all."

The International Trade Secretary said the UK-US working group had begun the process of analysing what sort of agreement can be reached after Brexit. "The first discussions will promote commercial continuity as the UK leaves the EU. But our ambitions are much wider.

"The working group provides a springboard, laying the groundwork for a comprehensive free trade agreement between our two nations, post-Brexit – to start a new and exciting chapter in our special relationship."

Fox said it is perhaps a cliché for a British politician to come to the US and speak of the special relationship. "But the fact the phrase is well-used doesn't make it any less true."

He added: "To realise ambitions at home, we will seek a full and comprehensive trading relationship with European neighbours. Yet we will also set our sights on wider and stronger ties with new friends and old allies alike as we seek to build a truly global Britain."

The US, he added, is Britain's largest export market, buying more than $200bn (£153bn) worth of services every year, more than France and Germany put together.

US firms employ more than 1 million people in the United Kingdom, and UK firms employ more than 1 million stateside, Fox said.

He declared these fundamentals will not change and "the UK will always be open for business".