Prime Minister Fumio Kishida on Monday pushed back against a suggestion by former leader Shinzo Abe that Japan discuss a nuclear-sharing arrangement with the U.S. amid the ongoing Ukraine crisis.

A U.S.-Japan nuclear-sharing deal would be “unacceptable given our country's stance of maintaining the three nonnuclear principles," Kishida said in parliament, referring to Japan’s 1967 commitment not to possess, produce or allow nuclear weapons on the country’s territory.

The prime minister made the remarks a day after Abe, who remains a heavyweight in the ruling Liberal Democratic Party as head of its largest faction, told a TV program that discussions on such a deterrent should not be taboo as the global security environment — especially in Asia — becomes increasingly fraught.