Boxing: Ukraine's Lomachenko returns to ring after fighting for his country

Instead of staying safely abroad, the two-time Olympic gold medallist known as "Loma" raced back to join the war effort.

"That's a clear decision, a normal decision, for any man when it's time to defend his home country," Lomachenko told Reuters through an interpreter while preparing for his bout against American Jamaine Ortiz on Saturday in New York, his first since the start of the invasion.

The uncertain early days of the conflict were the most difficult, he said.

"During those first days, the Russian military advanced very rapidly, taking over one city after another and going towards Kiev. So you could not get a clear understanding of what might happen tomorrow in your area, in your region," he said.

What he discovered while standing side by side with other volunteers was that Ukrainians are full of resolve and boundless bravery.

"We have a lot of courageous people, people who are willing to sacrifice for the sake of our nation," he said.

A former world champion in three weight classes, the 34-year-old lightweight said his experience in the ring helped him while he was serving -- but only up to a point.

"Both physically and mentally in boxing, you have to have this danger awareness when you're in the ring. You have to be constantly on the lookout in order to protect yourself, in order to not allow the opponent to inflict any damage," he said.

"Of course, you cannot compare a boxing environment to when you're out on the battlefield and you have rockets and bullets flying over you.

"But at the same time, I would think that I was more prepared compared to people who had no experience in any combat sports, so it gave me an edge."

Asked what his message was to Russian president Vladimir Putin, who has called Russia's actions in Ukraine a "special military operation," Lomachenko was blunt.

"He'll be judged by God," he said.

He said the situation on the ground had improved enough that he felt he could resume his boxing career and added that he was proud to represent Ukraine on the global sporting stage.

"Every time you go into a fight you represent your own country, you stand behind the colours of your flag," he said.

"And this time is no different. It's another opportunity to show the world who I am and to bring attention to Ukraine."