Zelensky, who turned 45 on Wednesday, thanked German Chancellor Olaf Scholz and US leader Joe Biden for their decision to send heavy tanks to Ukraine.

But Zelensky, who looked exhausted but determined, said Ukraine needed more weapons, including long-range missiles and jets.

"I've spoken with NATO Secretary General Jens Stoltenberg today," Zelensky said in a video address.

"We must also open deliveries of long-range missiles to Ukraine, it is important -- we must expand our cooperation in artillery," Zelensky said, also adding Ukraine needed jets.

"This is a dream. And this is a task."

He also urged Western countries to send tanks quickly and in sufficient volumes.

"Speed and volume are key now," he said, referring to deliveries and training of soldiers.

"The terrorist state must lose," Zelensky said, referring to Russia.

"The more defence support our heroes at the front receive from the world, the faster Russia's aggression will end."

The United States announced earlier Wednesday that it will provide 31 Abrams tanks to help Ukraine repel Russia's invasion, mirroring a similar move by Germany in the face of dire warnings from Moscow.

The twin announcements will come as a major relief for Kyiv, which has pleaded for months for heavy Western tanks to aid its battle.