Leaders of the Group of Seven nations have reaffirmed that they will remain united in supporting Ukraine.

The G7 leaders held an emergency online meeting on Tuesday in response to Russia's missile strikes across Ukraine.

Ukrainian President Volodymyr Zelenskyy joined at the start of the meeting, updating the participants on the situation in his country.

The leaders agreed that they will provide support to help ensure a democratic and prosperous future for Ukraine.

During the meeting, Japanese Prime Minister Kishida Fumio said Russia's attacks on civilians and civilian targets cannot be justified and should be denounced.

Kishida also said Japan recognizes neither Russia's so-called referendums held in some parts of Ukraine nor Moscow's illegal annexation of those regions.

He added that threatening to use nuclear weapons, let alone using them, is out of the question. He emphasized that Ukraine must not become the latest place to experience a nuclear attack.

Kishida briefed the other participants on Japan's sanctions against Russia.

He also made his case for coordinated responses to North Korea's repeated ballistic missile launches, and urged the other leaders to join hands in raising momentum for nuclear disarmament.

He told reporters after the talks that Japan will closely cooperate with the other G7 members to protect the rules-based international order.

He also said Japan will make appropriate decisions on whether to impose additional sanctions against Russia.

As for Russia's possible use of nuclear weapons, Kishida said the situation is unpredictable and must be monitored carefully.