The announcement came as leaders from both sides met in the Belgian capital for the EU-CELAC summit on Monday.
The European Union has committed to investing up to €45 billion in both Latin America and countries in the Caribbean by 2027.
European Commission President, Ursula von der Leyen, said that the money will take the form of concrete investments, including in the green energy sector, with the idea being to counterbalance, among others, China's influence in the region.
Also because the EU needs critical raw materials and South America holds 85% of the world's lithium reserves, among other rare earth minerals.
"What we want to discuss today is how to further connect our people and our businesses, how to reduce risks and strengthen and diversify our supply chains, and how to modernise our economies in a way that reduces inequalities and benefits all," von der Leyen said on Monday.
"All of this is within our reach if we get the EU-Mercosur agreement over the finish line, and we are committed to resolving any remaining differences as soon as possible."
In a meeting with von der Leyen, Brazilian President Lula da Silva also showed the country's commitment to finalising the ratification of the Mercosur trade deal.
But at the same time, he responded to European demands for additional commitments on high environmental criteria for stopping Amazon deforestation, which he considered "unreasonable".
"Everyone knows that Brazil will do its part on the climate issue. We have a commitment to zero deforestation in the Amazon by 2030," da Silva said.
"And during this debate we want to make the European Commission understand that there are 50 million inhabitants in the South American Amazon who need decent and dignified survival conditions."
Besides environmental concerns, the deal is also being contested in Europe for its implications for the agricultural sector, with Austria and France the more critical countries.