Ex Ukraine President Petro Poroshenko on Friday warned his successor Volodymyr Zelensky that not to trust on Russian President Vladimir Putin and said avoid meeting with him.

Poroshenko was defeated by Volodymyr Zelensky in this year’s polls, wrote in an editorial, “Don’t trust Putin. Ever and in anything. Putin manipulates everything: content, facts, figures, maps, emotions. He hates Ukraine and Ukrainians”.

“I sincerely advise to avoid meeting one-on-one with Putin, and if this is impossible, resist his KGB manipulations and flattery,” Poroshenko wrote in Ukrainska Pravda online daily.

President Zelensky will meet his Russian counterpart for the first time on Monday to hold talks on the conflict in Ukraine with mediation from Germany’s Angela Merkel and France’s Emmanuel Macron.

Last month, President Putin praised Zelensky as “likeable” and “sincere”.

The summit is the first since 2016 in this format and is awaited by some in Ukraine with hope and others with unease and concern that Zelensky may compromise the country’s interests when faced with political heavyweight Putin.

In September, Putin had said that a prisoner swap with Ukraine will take place “in the near future”, confirming a step that EU countries hope will lead to a breakthrough in relations between Moscow and Kiev.

Russia and Ukraine have been in discussions over exchanging prisoners held by both countries, who have been in conflict since 2014 after Moscow’s annexation of Crimea.