International Trade Secretary Liz Truss signed the agreement with her South Korean counterpart Yoo Myung-hee in London.

The two countries agreed to a preliminary deal in June, marking the first post-Brexit deal secured in Asia.

Trade between the UK and South Korea totalled £14.6bn ($17.7bn) in 2018.

The agreement is roughly in line with the terms of the existing Korea-EU free trade deal.

The UK has sought to secure agreements with its trading partners as it prepares to leave the European Union in October.

"My priority is to make sure that British businesses are fully prepared for Brexit and ready to trade on Thursday 31 October," Ms Truss said in a statement.

Ms Yoo said the agreement would "remove much Brexit uncertainty" from the economic partnership between the two countries.

South Korea is a global leader in electronics, steel and the auto industry, and its exports to the UK reached £5.2bn last year.

Asia's fourth largest economy exports mostly cars and ships to Britain, while it imports crude oil, cars and whisky.

Ms Truss said the agreement would allow firms such as luxury carmaker Bentley to "keep trading as they do today, and they will be able to take advantage of the opportunities that Brexit offers".

Warren Clarke, Bentley brand manager for South Korea welcomed the "stability" brought by the deal.

"As the first luxury car brand to enter the market in 2006 Bentley Motors sees South Korea as very significant to our future business plans."

The UK is pushing to reach agreements with its trading partners as the Brexit deadline looms.

So far, the UK has signed 13 trade continuity agreements with 38 countries, including Israel, Norway and Chile.