The most sensitive issues were left open pending a face-to-face meeting between Presidents Volodymyr Zelenskyy and Donald Trump.
European governments and the EU are insisting that any peace deal should allow Ukraine to freely organise its armed forces, which are now estimated at between 800,000 and 850,000 strong.
In her remarks, Kallas argued that Russia was engaging in diplomacy simply because "Putin cannot achieve his goals on the battlefield".
We still need to get from a situation where Russia pretends to negotiate to a situation where they need to negotiate," Kallas said.
"Only a 'peace through strength' strategy through exerting maximum economic, military and political pressure on Russia can stop the aggressor," said Latvia's Baiba Braže.
French President Emmanuel Macron, who co-chairs the coalition, called for a "strong" Ukrainian army without "limitations".
Kallas said the EU would make "major contributions" to the security guarantees by providing funding, training and support for the defence industry. »