About 30 Ukrainian men have died trying to illegally cross Ukraine's borders and avoid fighting in the war against Russia which started in 2022, the spokesman for Ukraine's border service told Ukrinform news agency.

"Some lost their lives while attempting to cross a mountain river or traverse mountains," said Andriy Demchenko, according to a Ukrinform report late on Monday.

"Overall, since the full-scale invasion began, about 30 people have died attempting to illegally cross the border."