According to Argentina's La Nación newspaper, the talk included plans for the summit, with Milei suggesting Argentina as the venue.
Zelensky, expressing gratitude on the X platform, said: "No balancing between right and wrong. Just clear support for Ukraine. This is noticed and appreciated by Ukrainians."
He also invited Milei to visit Ukraine.
Meanwhile, Milei, a controversial, far-right figure, has been recognized internationally, with congratulations from US President Joe Biden and Chinese leader Xi Jinping, Polish state news agency PAP reported.
Milei acknowledged Xi's greetings, signaling a potential softening of his rhetoric towards China, despite previous campaign assertions.
The new Argentine leader also responded positively to former US President Donald Trump's congratulatory message.