BIRMINGHAM, England, Oct 4 (Reuters) - Britain's foreign minister James Cleverly on Tuesday said Russian President Vladimir Putin's sequence of strategic errors must stop and that any use of nuclear weapons would lead to consequences.Putin has escalated its seven-month war in Ukraine with a military mobilisation and warnings of nuclear weapons use.read moreAsked how Britain would respond to the use of tactical nuclear weapons by Russia, Cleverly told a fringe event at the Conservative Party conference that he couldn't go into detail but there would be a response.Register now for FREE unlimited access to Reuters.com"It would inevitably be the case that the use of nuclear weapons by any country anywhere in the world would not go without a response," he said.Earlier Kremlin spokesman Dmitry Peskov said Moscow did not want to take part in "nuclear rhetoric" spread by the West, after Britain's Times newspaper reported that NATO had warned members Putin might test an atomic weapon on Ukraine's border."