"On top of the 12 Caesars already delivered, I took the decision (to deliver) in the coming weeks six additional Caesars," Macron told a news conference alongside Ukraine's President Volodymyr Zelensky, German Chancellor Olaf Scholz, Italian Prime Minister Mario Draghi and Romanian leader Klaus Iohannis.

"Europe is at your side. It will stay so until it needs to, until victory," the French leader said.

Earlier, he said Ukraine must "resist and win", during a visit to the war-scarred Kyiv suburb of Irpin -- the closest the Russian army got to the capital before retreating at the start of its invasion.

Caesars are highly prized for their accuracy and built by France's partly state-owned arms maker Nexter.

Ukraine demonstrated using the weapon to journalists including AFP earlier this week, as Kyiv pleaded for more Western weapons to counter Moscow's forces.