The ruling Liberal Democratic Party is set to begin internal discussions on nuclear deterrence, taking up the controversial issue of nuclear weapons-sharing with the United States despite the government's opposition to the idea, party lawmakers said Monday.

Russia's invasion of Ukraine and its threat of using nuclear weapons have prompted calls from conservative party members, including former Prime Minister Shinzo Abe, for Japan to discuss the topic.

The LDP's panel on national security will hear expert opinions on U.S. and European nuclear deterrence strategies on Wednesday and exchange views, the party sources said.