When Iuliia Mendel first met her future boss, Ukrainian President Volodymyr Zelenskyy, for an interview to become his press secretary, she didn't expect him to be dressed casually in

jeans and a T-shirt. Or that he would so thoroughly appraise her "on a psychological level." "He looked me in the eye throughout the interview," she tells PEOPLE.

"He wanted to assess from the start that he was seeing the real me." "He asked me why he should hire me, and I said: 'If a man from a poor background from some small

province in Ukraine can become the democratic president of the country, then a girl like me from a poor background in another province can become press secretary to the

nut. "He is addicted to fitness! That was evident from the first day I started working with him. We flew to Brussels and he had an interview with journalists which he took from the gym

on his training bike." "The interview wasn't planned — but the gym was — so he decided to combine the two." Mendel says that Zelenskyy, 44, always starts his day either

by jogging or going to the gym — even in a war zone. "Wherever we went, even it was the [contested region of] Donbas, he always went out running," she says. The president set up a

national fitness program that he promoted on his Instagram account called #HealthyUkraine. Unlike Zelenskyy, Mendel often came under attack in the media for the way she looked and dressed.

"In my country there are many demands about women and the way they look, and this means a female has to be 100 percent perfect in every way." A year after taking up her post,

rumors began circulating that she was having an affair with the world leader and was pregnant with his child. She dismisses the gossip, calling it fake news spread by Russia to discredit the

Ukrainian president, who has been happily married to his high school sweetheart, Olena Zelenska, for 19 years. The couple have two children. "Nobody could prove anything," she

tells PEOPLE. "I didn't discuss it (with him) because it was so ridiculous. We had a professional relationship." She adds: "It wasn't an attack on me, it was an

attack on the first couple of Ukraine." Zelenskyy reacted to the rumors with what Mendel says is typical humor, making a joke about her supposed "condition": "It was

during a very important meeting in his office just after the news first came out. He smiled across at me and said: 'How are you feeling?' Everyone around the room chuckled. He

wanted to break the ice." Zelenska, who was rumored in the media to have been hospitalized by the shock of the so-called revelation, didn't mention it to Mendel. "She of

course never raised the topic. It's ridiculous," Mendel says. "It just shows the power of Russian propaganda, because it was a big scandal." Another scandal broke after

she physically pushed journalists away from her boss. The incident hit the headlines and calls were made for her resignation. "But the next day, at a press conference, he turned to me

smiling and said: 'You didn't push anyone, did you Yul?' He uses his humor as a political tool to put people at their ease," she says. _NEVER MISS A STORY — SIGN UP FOR__

PEOPLE'S FREE DAILY NEWSLETTER__ TO STAY UP-TO-DATE ON THE BEST OF WHAT PEOPLE HAS TO OFFER._ Zelenskyy is now viewed on the world stage as a steely warrior-leader. But he first rose

to fame in his home country as an actor, playing the role of a simple man who becomes president of Ukraine in the TV comedy _Servant of the People_. He named his political party after the

top-rating show before running for office. Talking about the series, which ran for four years, Mendel says "it was great PR." "People had been watching him and they loved him

because he was the King of Humor in Ukraine." But as she points out, "it is a very different thing to play the role of a president in front of the cameras and to actually work as a

president." She tells PEOPLE he can be deadly serious when required, recalling how taken aback Russian President Vladimir Putin was by Zelenskyy's persistence during their first

round of negotiations in Paris in 2019. "Putin kept looking around to his advisors saying, 'We need to double check on that.' I could see his confidence was rather shaken. But

Zelenskyy would never give up. He'd say: 'I don't think you understand what I'm saying here.'" The two leaders have very different values, Mendel adds.

"Putin promotes so-called traditional family values, but he himself is divorced and there are a lot of reports of him having different women. Zelenskyy doesn't have to promote his

family values. He is very proud of Olena. He listens to her advice." Mendel resigned from her post as Zelenskyy's spokesperson before _The Fight of Our Lives_ was published in

Ukraine last year. "I told [Zelenskyy] that I was publishing the book," she says. His reaction? "He didn't want to read it or see it or contribute. And he didn't ask

what I was writing. But when I left office he wished me good luck." The English-language version of _The Fight of Our Lives_ will be published by Simon & Schuster on Sept. 13. _The

Russian attack on Ukraine is an evolving story, with information changing quickly. Follow __PEOPLE's complete coverage of the war here__, including stories from citizens on the ground

and ways to help._