NATO Secretary General Jens Stoltenberg is Saturday expected to tell a major security forum in Germany that allies must provide Ukraine what it needs to defeat Russia, as Kyiv pleads for more weapons, according to AFP.

"We must give Ukraine what they need to win and prevail as a sovereign, independent nation in Europe," he will tell the Munich Security Conference, according to excerpts of his speech seen by AFP.

His comments to world leaders will come ahead of the one-year anniversary of Russia sending its troops into Ukraine, bringing war to Europe for the first time in decades and upending the global security landscape.

Allies, led by the United States, have sent billions of dollars of armaments to Kyiv, from artillery to air defence systems, but Ukraine says it needs more to launch a successful counter-offensive.

Stoltenberg will back Kyiv's calls, telling the conference "we must sustain and step up our support for Ukraine.

"Putin is not planning for peace. He is planning for more war."

Opening the conference Friday, Ukrainian President Volodymyr Zelensky urged allies to speed up their support, while European powers pledged to intensify their backing.

Stoltenberg will also warn that Russia's military operation has exposed the dangers of Europe's over-reliance on authoritarian regimes and should serve as a lesson.

"We should not make the same mistake with China and other authoritarian regimes," he warned.

The Ukraine war has stoked fears among Western powers that China could try something similar in Taiwan, a self-ruled democratic island that Beijing claims as part of its territory.

The three-day security conference is being attended by dozens of senior figures, including the leaders of Germany and France, US Vice President Kamala Harris, US Secretary of State Antony Blinken.