The EU and Cuba signed a renewable energy deal on Tuesday, a step towards normalising relations in defiance of Washington's continuing hardline stance on Havana.
As it scrambles to save the Iran nuclear deal after US President Donald Trump ditched it last week, the EU sought to add substance to its landmark cooperation agreement with Cuba, which came into effect in November.
EU diplomatic chief Federica Mogherini has condemned the US economic blockade of the communist island as "obsolete" and "illegal", but under Trump the US has rolled back the rapprochement championed by his predecessor Barack Obama.
Mogherini and Cuban Foreign Minister Bruno Rodriguez Parrilla led the first meeting of the EU-Cuba Joint Council in Brussels.
The highlight was the signing of an 18 million euro ($21.5 million) project to support Cuba's goal of getting a quarter of its energy from renewable sources by 2030.
The EU also plans to finance a food security support programme for the island with a contribution of 19.7 million euros.
"Today we celebrate an important step in relations between the EU and Cuba," Mogherini said.
"We want to construct a closer relationship based on open and frank dialogue and mutual respect and effective cooperation."
Cuba turned a page in its history last month when Miguel Diaz-Canel took over as president after nearly 60 years of rule by revolutionary leader Fidel Castro and then his brother Raul.
Havana and Brussels also launched dialogues focusing on five areas including sustainable development, non-proliferation, human rights and unilateral measures.
The last section will deal with the US embargo. Havana is hoping the EU will prove to be an ally against Trump.
The agreement with Cuba, so far ratified by 13 of the 28 EU member states, can be suspended in case of grave rights abuses.
The EU's 28 countries are the main foreign investors in Cuba, mainly in the tourism and building sectors, the EU says.
The bloc imported some 470 million euros' worth of Cuban goods in 2017 and exported more than 2.0 billion euros' worth.
Cuban Foreign Minister Bruno Rodriguez Parrilla, right, with EU diplomatic chief Federica Mogherini, centre, in Brussels on Tuesday