March 11 marks exactly 13 years since a massive earthquake and tsunami hit northeastern Japan. A nuclear expert in war-torn Ukraine says he is remembering the areas affected by the accident at the Fukushima Daiichi nuclear plant triggered by the disaster in 2011.

Serhiy Kireev heads a government research laboratory about 12 kilometers from the Chornobyl nuclear power plant in northern Ukraine.

He offered silent prayers to those affected by the 2011 disaster at a memorial monument jointly built by Japanese and Ukrainians near his lab.

Kireev was among those who responded to the nuclear crisis at the Chornobyl power plant in 1986 during the Soviet era.

He offered assistance to Japan when meltdowns occurred at the Fukushima Daiichi plant, including helping Japanese experts measure radioactive contamination in the environment.

Kireev has often visited the Fukushima Daiichi plant to share Ukrainian experts' knowledge with Japanese counterparts. His laboratory and Fukushima University have also been conducting a joint environmental study near the Chornobyl plant.

Kireev said he will never forget what happened to people in Fukushima and Ukraine, and that he hopes those displaced by the nuclear accidents can someday return to their hometowns.

He added that he will continue to work hand-in-hand with Japanese researchers so that the day will come as early as possible.

He said Russian troops temporarily occupied his lab in the wake of their invasion of Ukraine and destroyed or stole its computers and dosimeters. Japan helped the lab to resume operations by providing replacements.

Kireev thanked Japan for being one of the countries to provide assistance.