Boris Johnson has reaffirmed Britain’s support for Ukraine, cautioning against “Ukraine fatigue” as Russia’s invasion enters its fifth month. Speaking to reporters on his arrival at RAF Brize Norton after his trip to Kyiv, the prime minister said: “When Ukraine fatigue is setting in, it is very important to show that we are with them for the long haul and we are giving them the strategic resilience that they need. “The Russians are grinding forward inch by inch and it is vital for us to show what we know to be true, which is that Ukraine can win and will win.” Johnson made an unannounced trip to Ukraine on Friday – his third since the Russian invasion began – to meet the Ukrainian president, Volodymyr Zelenskiy. During the visit he announced that the UK would oversee a three-week training programme for Ukrainian soldiers. The visit was not without controversy, with critics accusing him of showing “total contempt” for the north of England after pulling out of a conference in Doncaster at the last minute. Tory MPs in the Northern Research Group (NRG) were promised that Johnson would be the headline speaker at their event for hundreds of activists, but heard of the cancellation just hours before he was due to speak. One source told the Guardian that the meeting with Zelenskiy had been scheduled in the “government grid” for at least a week. Discussing the prospect of a Russian victory in the war, Johnson stressed that Zelenskiy should not be pressured into accepting a “bad peace”. He said: “It would a catastrophe if Putin won. He’d love nothing more than to say: ‘Let’s freeze this conflict, let’s have a ceasefire like we had back in 2014.’ “For him, that would be a tremendous victory. You’d have a situation in which Putin was able to consolidate his gains and then to launch another attack. “We’ve got to make it clear that we are supporting the Ukrainians in their ambitions … to expel the Russians, expel Putin’s armies, from everything that he has obtained since 24 February and make sure the Ukrainians are not encouraged to go for a bad peace, something that simply wouldn’t endure.”