Former Japanese Prime Minister Yoshiro Mori, known for being gaffe-prone, on Wednesday urged the government against excessive support for Ukraine, saying Russia will not lose its ongoing war in the Eastern European nation.

"I wonder why" Japan has put in "such a big effort to support Ukraine," the 85-year-old member of the ruling Liberal Democratic Party said in a speech at a reception, adding that Tokyo "had built relations" with Moscow, which invaded its neighbor in February 2022.

"It is unthinkable that Russia would lose the war. If that happened, something harder would happen," said Mori, who was active in strengthening bilateral ties with Russia through talks with Russian President Vladimir Putin.

Mori served as Japanese prime minister for about one year from April 2000, as the approval ratings for his Cabinet struggled against the backdrop of his repeated gaffes.

After he retired as a lower house lawmaker about a decade ago, Mori met with Putin as a special envoy of then Prime Minister Shinzo Abe, who was assassinated during an election campaign speech in early July last year.

In November, Mori also said at a political gathering in Tokyo that he could not "quite understand why only President Putin has been criticized," while saying Ukrainian President Volodymyr Zelenskyy has been "making many Ukrainian people suffer."

Mori was the chief organizer of the Tokyo Olympics, which was postponed for one year from 2020 due to the COVID-19 pandemic, but resigned in February 2021 before the games began after coming under fire over sexist remarks.

On Tuesday, Chief Cabinet Secretary Hirokazu Matsuno, the government's top spokesman, said Japan will "continue to offer assistance" to people in Ukraine, who have been facing a "national crisis."