Britain said it will maintain duty-free access to its markets once it has left the European Union for goods from nearly 50 developing countries including Bangladesh, Sierra Leone and Haiti.
The government said around 48 countries would continue to benefit from tariff-free exports on all goods other than arms and ammunition to the UK and that once it had left the EU in 2019 it would explore options to expand trade relations further.
"Our departure from the EU is an opportunity to step up to our commitments to the rest of the world, not step away from them," International Trade Secretary Liam Fox said in a statement.
"Free and fair trade has been the greatest liberator of the world's poor, and today's announcement shows our commitment to helping developing countries grow their economies and reduce poverty through trade."
Britain embarked on its negotiations to leave the EU earlier this week, agreeing to deal first with EU priorities such as a possible "Brexit bill" before discussing future trade deals with the bloc.
According to the government, around 20 billion pounds a year of goods were shipped to Britain from these developing countries, accounting for around half of its clothing, a quarter of its coffee and other goods such as cocoa, bananas and roses.