"We expect (it to) speed up weapons to Ukraine, we expect (them) to continue to support Ukraine," he told reporters when asked what Ukraine could expect from the gathering.

"We need anti-rocket systems. We see that every day Russian rockets destroy our cities, kill civilians, destroy infrastructure," he added.

Klitschko, a world heavyweight boxing champ whose nickname is "Dr Ironfist", said "support for Ukraine is key for the return of peace in Europe".

Over 40 world leaders, including US President Joe Biden, his French counterpart Emmanuel Macron and British Prime Minister Boris Johnson, are in Madrid for the meeting.

Russia's invasion of Ukraine is set to dominate talks which wrap up on Thursday.