"We as a country would like to join NATO and have reached out to them for years," he told the German daily Bild.

"But the process has stalled. There are causes and reasons for that. Not only Russia is against Ukraine joining."

Zelensky said "individual NATO member countries support Moscow in its position", calling it an "open secret".

He declined to name the countries, saying he was still hopeful they would come around.

"We don't have it easy with these countries and don't want any risks or diplomatic conflicts," he said.

Zelensky said the Ukrainian people should be able to decide whether the country joins NATO but that a referendum at this point would make little sense.

"The road into NATO and the EU is a very long one. Ukraine needs some security guarantees along the way," he said, asking for the support of NATO member states.

"NATO is the guarantee for security, that's what we want to achieve. This guarantee means for us that we won't lose our independence," he said.

Ukraine has long said it wants to join the US-led military alliance but has been told by NATO that it is far from being ready to win acceptance.

The Kremlin is insisting NATO must never grant membership for Ukraine and must roll back its forces near Russia's borders.

But the West has rejected what it calls a bid by Moscow to dictate the future of independent partners and threatened Moscow with "severe costs" if it launches further incursions into Ukraine.