Poroshenko's political party, European Solidarity, said the former president had scheduled only meetings in Poland and the United States and warned the SBU security service against becoming involved in politics.
Orban has frequently been at odds with Zelenskiy on several issues related to Ukraine's EU membership bid.
European Solidarity, in its statement, called for dialogue with Orban who, it said, had a veto right over accession talks.
Poroshenko, president from 2014 to 2019, accused Zelenskiy's administration on Friday of cancelling the permission and playing politics ahead of elections.
Additional reporting by Boldizsar Gyori in Budapest, Editing by Ron Popeski and Daniel WallisOur Standards: The Thomson Reuters Trust Principles.
Persons:
Petro Poroshenko, Gleb Garanich, Poroshenko, SBU, Viktor Orban, Vladimir Putin, Orban, Putin, Oleksandr Korniyenko, Poroshenko's, Zelenskiy's, Zelenskiy, Boldizsar Gyori, Ron Popeski, Daniel Wallis
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REUTERS, Rights, European, Hungarian, European Union, Ukraine, EU, European Solidarity, Thomson
Locations:
Ukraine, Kyiv, Russia, European Solidarity, Poland, United States, Moscow, Budapest