According to TASS, Zelensky said this during a joint press conference in Kyiv with Latvian President Egils Levits.
“Artillery is number one, this is what we need,” the Ukrainian leader admitted.
In addition, he added, the Ukrainian army needs to supply aircraft and train pilots to fly them.
Zelensky also pointed to a "certain deficit" in the number of tanks.
In February, a former adviser to the head of the Pentagon, retired US Army Colonel Douglas McGregor, said that the Ukrainian army was forced to retreat due to a lack of ammunition.