My understanding is that it will be decided one day by the International Court of Justice (ICJ), the UN court responsible for solving disputes between nations. South Africa alleges that Israel is committing genocide against the Palestinians and filed its complaint in December 2023.
Wikipedia have a list of state positions on the question of genocide in Gaza. Most countries in the West who have publicly expressed an opinion either disagree with the term Genocide at the moment, (US, UK, Germany, Greece, Hungary, Italy) or say they will defer to the ruling in the ICJ case (Belgium, Canada, Norway).
The French position is unclear although France's ambassador to the UN has previously said that France would "see what the the ICJ decide on this matter and we'll make sure that we'll support the outcome of the decision".
Western countries who have already declared it a genocide before the ICJ ruling are Ireland, Slovenia and Spain according to Wikipedia.
Also according to Wikipedia, a large group of states in the Islamic world, parts of Africa and South America describe Israel's actions as genocide. These include Turkey, Malaysia, Egypt, Brazil, Chili and Columbia.
The Organisation of Islamic Cooperation (OIC), the Arab League and the African Unions have collectively endorsed the characterisation of Israel's actions as genocide.
en.wikipedia.org/wiki/List_of_state_positions_on_the_Gaza_genocide