A shipment of British goods - including signed Beano comics - are to be sent to Australia and New Zealand to mark the start of two new post-Brexit trade deals.
"Businesses up and down the country will now be able to reap the rewards of our status as an independent trading nation and seize new opportunities, driving economic growth, innovation and higher wages," she said.
The deals mean all tariffs on UK goods exports to Australia and New Zealand will be removed, while the government says red tape has also been slashed for digital trade and work visas.
Alongside the new trade deals, ministers say young Britons will benefit from opportunities to travel to Australia with the expansion of the shared Youth Mobility and Working Holiday Maker visa schemes.
The government previously said it expects its deal with Australia to add £2.3bn to the UK economy, and a further £800m added from the trade deal with New Zealand.
However, fears have been raised over the impact on the UK's farming sector, with the National Farmers' Union previously warning it could cost the industry up to £150m.
Plaid Cymru MP Ben Lake, the party's agriculture spokesman in Westminster, said the trade deals marked the "beginning of a worrying chapter" for Welsh farming - with Australia and New Zealand both among the world's biggest producers of lamb.
Ministers have previously described anxieties over the deal as "misplaced" and said that much of New Zealand's lamb is exported to China.
To mark the starting of the deals, international trade minister Nigel Huddleston will on Wednesday tour DHL's Southern Distribution Centre near Heathrow to see off two hand-picked consignments of British goods.
They include Beano comics signed by the comic's editor John Anderson, Penderyn single malt Welsh whisky, Brighton Gin, The Cambridge Satchel Co. bags and Fever-Tree mixers.
The packages, which include an England cricket top signed by James Anderson and Emma Lamb and a Welsh rugby shirt signed by the men's team, will be sent from the government to the Australian and New Zealand trade ministers.
"Australia and New Zealand are two of our closest friends and like-minded partners and our trade deals secure favourable terms for British exporters, removing tariffs on all UK goods and slashing red tape," he said.
In July, the age limit for UK applicants going to Australia will go from 30 to 35 years old.
From July next year, Britons will also be able to stay in Australia for up to three years without having to meet specified work requirements.
It comes after Rishi Sunak announced last month that the UK will benefit from almost £18bn of extra private investment from Japan.
Mr Sunak also said he envisioned even greater ties will come after the UK joined the CPTPP Pacific trading bloc, saying the "sky's the limit".
Earlier this year it was announced that the UK would join the bloc, which consists of countries including Australia, New Zealand, Canada, Chile and Japan.
The UK has struck more than 70 trade deals since leaving the EU - but agreements with major players such as China and the US have remained elusive so far.
Trade with the EU also declined following the end of the UK's post-referendum transition period, while the latest data published in a House of Commons report this month warned that UK exports to the EU remain below 2019 levels.