Japan was not among the nations Ukraine thanked in a social media video highlighting support it has received in its fight against Russia, with Japan's top diplomat saying Tuesday the omission was a result of Tokyo not providing lethal weapons.

"We received an explanation from the Ukrainian side that the gratitude shown was in the context of thanking countries for providing weapons assistance," Foreign Minister Yoshimasa Hayashi said during a news conference, adding that the video was a message from a Ukrainian military leader.

"Ukraine expressed gratitude again to us for offering humanitarian and financial assistance as well as defense equipment," Hayashi added.