Nato Secretary General Jens Stoltenberg's comment came in the context of an informal meeting among EU Defence Ministers in Bratislava on military cooperation among the bloc, EFE news reported.
"There is no contradiction between strong European defence and strong Nato," Stoltenberg said.
He added that each would reinforce the other and had to be complementary, rather than be a duplication of structures.
During Tuesday's meeting, defence representatives of EU states were to discuss a Franco-German proposal on reinforced EU defence and security, though without the creation of an EU army.
Germany's Defence Minister Ursula von der Leyen highlighted that Franco-German proposals on security and defence would not go against Nato and that it was important to have a strong Europe with a strong defence, which would strengthen Nato too.
Britain's Defence Minister Michael Fallon made it clear that Britain would not accept an EU army, saying that it would undermine Nato and threaten the sovereignty of member states.
