She noted that the bloc had achieved a lot, including higher defence spending, but that serious shortfalls remained.
Ukraine, she added, "urgently needs air defence," including US Patriot systems.
Defence ministers of the 27 EU states are due to discuss the issue in Brussels on Monday.
Speaking on the Middle East, Kallas addressed an Italian proposal to strengthen the EU's Aspides naval mission in the Red Sea, saying more "assets" would be needed.
The EU foreign policy chief said she had urged member states to contribute more but had so far received no new, binding commitments.
Aspides, launched in February 2024, protects commercial shipping in the Red Sea, the Gulf of Aden and adjacent waters.
It was set up after Yemen's Houthi rebels stepped up attacks on ships in the Red Sea, as part of a wider conflict in the Middle East.
(ał)
Source: IAR, PAP