Russian President Vladimir Putin.SERGEI ILNITSKY / POOL / AFPRussian President Vladimir Putin has responded to Volodymyr Zelenskyy's nuclear comments.The Ukrainian president had suggested that Kyiv would seek nuclear weapons if it could not join NATO.Zelenskyy later walked back his statement.Russian President Vladimir Putin has said Ukrainian President Volodymyr Zelenskyy's comments about nuclear weapons earlier this week were a "dangerous act of provocation."Putin was referring to Zelenskyy's suggestion that Kyiv would seek nuclear weapons if it could not join NATO.Speaking at the European Council summit in Brussels on Thursday, the Ukrainian president referred to the 1994 Budapest Memorandum, which resulted in Ukraine giving up its Soviet nuclear weapons in exchange for security assurances."Who gave up nuclear weapons?