KYIV -- Ukrainian first lady Olena Zelenska is "afraid" the world's attention is turning away from the war, more than 18 months since Russia launched a full-scale invasion of her country.

Speaking with ABC News in an interview in Kyiv, Zelenska said, "sometimes people become reluctant, people talk about Ukraine fatigue."

"This is the topic of our existence. We can't stop fighting for ourselves. So my message is, please don't stop to help us fight," Zelenska said.

Zelenska is hosting The Summit of First Ladies and Gentlemen on Wednesday in Kyiv, an international association of spouses of the world's top leaders. Founded by Zelenska in 2021, this year the attendees include former U.S. first lady and Secretary of State Hillary Clinton. The summit places a strong emphasis on mental health.

Zelenska said, "It's a pressing issue around the world, but obviously it becomes a burning issue in a country that's at war, when every Ukrainian is dealing with the consequences of events that we're all witnessing."

When asked about the mental health of her husband, Ukraine President Volodymyr Zelenskyy, the first lady said it's something she'd like to discuss with him more often.

"He belongs to the category of people who would try to deal with things on their own. Until the end. Actually he's a very tough man with high resilience. But everyone needs a rest sometimes. He does a lot of sport when he gets the opportunity. It helps him a lot," she said.

Since the beginning of the war, the first lady has spoken out about the psychological impacts of this war on children and helped implement programs to rehabilitate Ukraine's most vulnerable.

"Extra hours are being added to the school curriculum to teach the kids about their mental health, and every teacher will have a special course on providing psychological help and support," Zelenska said. "The aim is to wrap every child with an armour of mental resilience."

Ukrainian children returned to school on September 1 and Zelenska said her son sometimes has to learn from the school shelter, while her daughter is starting her second year of university.

"This year they're trying to study completely offline. And for her it's a novelty because for many years they were studying in a mixed format. She has never seen all her fellow pupils and friends together in person, so she's very happy," she said.

Only one third of primary children in second and third grade children will be learning in person, according to UNICEF. In the city of Kharkiv, subway stations have been turned into classrooms, in other cases bunkers are refurbished so that lessons aren't interrupted when the air raid sirens go off.

Damian Rance, Chief of Communications for UNICEF Ukraine based in Kyiv, said this is having "significant mental health effects for children because schools are not just about formal education, it's about social and emotional development as well."

"We're going to see significant issues unless we collectively address education as one of the major priorities," Rance said.

A study by UNESCO found that 75% of Ukrainian schoolchildren experienced some degree of stress, while around a third of Ukrainian teenagers have been diagnosed with post-traumatic stress disorder.

Zelenska is also worried about children being indoctrinated by Russia.

The Ukrainian government now says Russians have deported or forcibly relocated more than 19,500 Ukrainian children since the war began. UN investigators say it amounts to a war crime.

Zelenska said she believes this is part of a long term strategy to brainwash children in the country.

"This is indeed a conscious policy," she said. "Because all the children we've managed to return say that the first thing that was done with them was so-called "patriotic re-education". That is, they were taught that they are no longer Ukrainians, that they are Russians, which they're told is the country they should love."

The first lady also addressed questions about women who encourage their partners to avoid the military, saying it is not her position to decide for them when it comes to matters of life and the fear of death, but that they should work within the framework of the law.

"The only thing I can advise now," she said, "Is how you will look into the eyes of the people who will live around you? What will you say to them? How will you make excuses?"