President Vladimir Putin said the situation in four areas of Ukraine that Moscow had declared part of Russia was “extremely difficult” and ordered security services to step up surveillance on its borders and combat new threats.

Putin told operatives they needed to significantly improve their work, in a speech that was one of his clearest public admissions yet that the invasion he launched almost 10 months ago is not going to plan. It followed a visit to close ally Belarus that fuelled fears, dismissed by the Kremlin, that the country could help Russia open a new invasion front.