Japan's foreign minister travelled Sunday to Chernobyl in Ukraine, the site of the world's worst nuclear disaster, to compare notes on relief efforts following Japan's own disaster at Fukushima, officials said.

Foreign Minister Fumio Kishida's trip is "the first visit to Ukraine by a Japanese foreign minister over the past seven years," a spokesperson for the Japanese embassy told AFP.

As part of his three-day visit, Kishida went on a fact-finding mission to Chernobyl with the aim of sharing experience in overcoming the consequences of nuclear disasters, the spokesperson said.

In Chernobyl, he met with the station's director, an AFP photographer said. No other details were immediately available.

On Monday, Japan's top diplomat is expected to hold talks with Ukraine's Foreign Minister Leonid Kozhara.

The two men will discuss cooperation in studying and overcoming the consequences of nuclear disasters in Japan and Ukraine, said a spokesman for the Ukrainian foreign ministry without providing further details.

In March 2011, an earthquake and tsunami caused meltdowns at the Fukushima nuclear plant in northeast Japan.

While no one is officially recorded as having died as a direct result of the meltdown at the reactors, large areas around the plant had to be evacuated, with tens of thousands of people still unable to return.

The explosion at reactor number four at the Chernobyl power plant in the early hours of April 26, 1986 sent radioactive fallout into the atmosphere that spread from the Soviet Union across Europe.

According to Ukrainian official figures, more than 25,000 of the cleanup workers from then-Soviet Ukraine, Russia and Belarus have died since the disaster.

The two catastrophes are the world's only nuclear disasters to have been categorised as level seven on the United Nations' seven-point International Nuclear Event Scale (INES).

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