Delegates from Ukraine and Russia have held talks in Belarus, but these talks have yielded no progress thus far. Zelensky and Russian President Vladimir Putin have yet to hold talks.
"This is the time to meet, to talk, time for renewing territorial integrity and fairness for Ukraine," Zelensky said in a Facebook video. "Otherwise, Russia's losses will be such that several generations will not recover."
Zelensky's plea comes as Russia claims its troops have entered the port city of Mariupol. However, Russia is struggling to make progress elsewhere in Ukraine. They continue to face fierce resistance on the outskirts of the capital Kyiv and have been unable to get any closer than 30km east of the city.
Britain's defence ministry claims that Russia is facing a shortage of essentials like food and fuel to supply to its troops.
Russia's defence ministry has focussed on its successes in Mariupol.
"In Mariupol, units of the Donetsk People's Republic, with the support of the Russian armed forces, are squeezing the encirclement and fighting against nationalists in the city centre," the ministry announced.
Over 9,000 citizens have been evacuated from the city.