Regardless of the outcome, officials said the meeting itself marked a step towards stronger ties.
"The most important issue of the meeting is the meeting itself," Argentine Undersecretary for Latin American and Caribbean affairs Gustavo Martinez Pandiani told a small group of reporters in Brussels.
The EU has said it wants a joint declaration condemning Russia, but knows this will be difficult to achieve.
The EU and Argentina will sign a memorandum of understanding on energy cooperation before the summit starts.
The EU may also offer details on plans to invest 10 billion euros ($11.2 billion) in CELAC infrastructure projects, part of its Global Gateway initiative.
Persons:
Gustavo Martinez Pandiani, Luiz Inacio Lula da Silva, Philip Blenkinsop, Barbara Lewis
Organizations:
European Union, UN, European, EU, Mercosur, Thomson
Locations:
BRUSSELS, America, Caribbean, EU, Ukraine, China, Caribbean States, Brussels, Argentine, Russia, Nicaragua, Bolivia, Cuba, El Salvador, Beijing, Mexico, Peru, Venezuela, Chile, Argentina, Brazil, Paraguay, Uruguay