Theresa May is to announce a new oil and gas partnership with Colombia as she welcomes the South American country's president to 10 Downing Street.
The talks come on the second day of President Juan Manuel Santos's state visit to the UK, which on Tuesday saw him hosted by the Queen at a banquet at Buckingham Palace.
Mrs May was expected to tell him that Colombia is one of Britain's most important partners in Latin America, with which the UK will aim to boost trade following withdrawal from the European Union.
The two leaders will announce a new double taxation agreement to help businesses and employees in both countries.
And the Prime Minister will announce £1 billion in UK export finance to encourage investment in healthcare and energy projects.
Mrs May is expected to say: "Colombia is one of Britain's most important partners in Latin America, and this visit provides an opportunity to strengthen the ties that have existed between our countries for more than 200 years.
"As the UK prepares to leave the EU, I am determined that Britain should become the global champion of free trade, and that means boosting trade with fast-growing economies like Colombia.
"A peaceful, prosperous Colombia is in both our interests, and I look forward to working with President Santos to forge an even stronger partnership in the years ahead."
Downing Street said that the UK has been Colombia's third largest foreign investor over the past decade, with a trading relationship worth £1 billion last year.
Bringing together the cities of Aberdeen and Barranquilla, the new oil and gas partnership will share best practice in areas like regulation, supply chain development and training.
The Prime Minister and President are also expected to discuss how the UK can support efforts to secure a lasting peace agreement in Colombia, following last month's referendum which narrowly rejected Mr Santos's deal to end conflict with Farc guerrillas.