An international conference has opened to discuss how to help people in Ukraine survive the winter as Russian strikes on energy infrastructure are causing massive power outages.

The meeting began in Paris on Tuesday, hosted by the French government. It brings together delegates from more than 40 countries, including Japan and European nations. Ukraine's Prime Minister Denys Shmyhal and First Lady Olena Zelenska also attended the conference.

French President Emmanuel Macron spoke at the start of the gathering, denouncing the Russian attacks as war crimes. He said Russia was aiming to plunge Ukrainians into despair.

Macron called for international unity to come up with specific aid for Ukrainians.

Ukrainian President Volodymyr Zelenskyy addressed the meeting via video link, asking for more assistance. He said Russia had attacked many power facilities, causing blackouts for millions of people.

Delegates will announce new humanitarian support measures for Ukraine. They will also discuss, with participation by private-sector firms, how to restore the country's infrastructure as early as possible.

The participants also plan to launch a mechanism to internationally share what kind of support Ukraine needs.