"This is what we must focus on first -- we must stop Russian drones and missiles. This means more air defence supplies and investments in interceptor drones, air defence systems, and missiles," Zelensky said.

"I urge all our partners -- increase your investments. When Russia increases its attacks, we cannot have a shortage of funding."

Zelensky was speaking at the start of the two-day Ukraine Recovery Conference, aimed at mobilising support and investment for his country as it faces its fourth year of conflict with Russia.

It took place as Russia hammered Ukraine's capital with its second large-scale drone and missile barrage in as many nights, killing at least two people.

Zelensky said the attacks proved Russian President Vladimir Putin was not interested in peace, saying he was escalating the violence.

"This is exactly what Putin wants for our people to suffer, to flee Ukraine and for homes, schools, for life itself to be destroyed," he said.

The meeting hosted by Italian Prime Minister Giorgia Meloni gathers hundreds of companies, officials, as well as 15 heads of state including EU chief Ursula von der Leyen and German Chancellor Friedrich Merz.

It focuses on Ukraine's long-term recovery, as well as on its immediate needs to fight off Russia's invasion.