It is thought the Ukrainian president will arrive in Hiroshima on Sunday in a bid to secure further military support for a planned counter-offensive.
Zelensky was in Saudi Arabia for an Arab League summit.
Of the Arab League nations, only Syria has openly supported Russia’s invasion.
But other members have sought to preserve good relations with Moscow.
Mr Zelensky said: “Unfortunately, there are some in the world and here among you who turn a blind eye to those [prisoner of war] cages and illegal annexations.
“I’m here so that everyone can take an honest look, no matter how hard the Russians try to influence, there must still be independence.”
The Ukrainian leader also told the meeting in Jeddah that his country was defending itself from colonisers and imperialists.
Host nation Saudi Arabia has supported a UN resolution calling for Russia to withdraw its troops and pledged $400m in humanitarian aid to Ukraine.
However it has rejected imposing sanctions on Russia and painted itself as neutral in the conflict.
Saudi Crown Prince Mohammed bin Salman renewed his offer for Saudi Arabia to mediate between Moscow and Kyiv to end the fighting at the summit.
The country helped broker a prisoner exchange between Russia and Ukraine last year..
Syria meanwhile has only just been readmitted to the Arab League - its leader Bashar al-Assad told the summit there was an historic opportunity for the region to reshape itself without foreign interference.
Mr Zelensky also took aim at Iran, which is not a member of the Arab League, for supplying Shahed drones to Russia. Iran denies supplying drones for the conflict.
The Ukrainian leader is expected to travel from Saudi Arabia to the G7 summit, although his office has not confirmed the visit.
The G7 summit kicked off on Friday with a renewed condemnation of Russia and an announcement of further sanctions.
The group of seven nations, made up of the US, UK, France, Italy, Germany, Canada and Japan, represent the world’s richest democracies. This year, eight other countries including Australia and India have also been invited.
In the past few days Zelensky has visited Italy, Germany, France and the UK, where he nailed down promises of military support. He also continues to push allies to provide advanced fighter jets to Ukraine, but so far no country has committed to directly providing them.