The European Commission, European Investment Bank, European Bank for Reconstruction and Development and the World Bank will invest the funds to improve and expand so-called "Solidarity Lanes".
These are routes to bring Kyiv's huge agricultural harvest -- and some other imports and exports -- overland from the war-torn country and onto the world market via safer European Union ports.
"Where Russia sowed destruction, Europe restored hope," European Commission President Ursula von der Leyen said, announcing the additional funding on social media.
Russian forces launched a full-scale invasion of Ukraine in February and, despite a UN- and Turkish-brokered deal to allow grain shipments, the fighting has disrupted the harvest and exports.
Ukraine is one of the world's biggest food suppliers and Brussels was keen to head off the threat of famine in parts of Africa and the Middle East, while supporting Kyiv's agriculture sector.
Friday's announcement commits a major funding boost to the project, with cash to reduce waiting times for trucks and trains crossing to Poland and Romania from Moldova and Ukraine.
An urgent grant of 250 million euros in European Commission funds will provide mobile equipment to improve the flow of traffic at border crossings and access routes, the statement said.
Longer-term funding from the development banks brings the total announced on Friday to around one billion euros and will supports repairs and development to road and railway freight infrastructure in Ukraine.