Three people from the Netherlands were killed in the attack on Brussels airport departure hall, the Dutch Foreign Ministry said in a statement on Friday.
The victims included a 41-year-old woman from Deventer, on the border with Germany, and a brother and sister from Maastricht who lived in New York.
"It is terrible that these people were killed through the arbitrariness of terror," Dutch Foreign Minister Bert Koenders said.
A university student and a government worker from Belgium and a Peruvian woman married to a Belgian were confirmed dead earlier this week.
Most of the 31 victims' identities remain unknown, and Brussels Mayor Yvan Mayeur has warned that identifying victims will "take some time."