British Prime Minister Boris Johnson has said "we need to steel ourselves for <a href="https://www.thenationalnews.com/world/us-news/2022/06/17/russian-media-show-images-reported-to-be-us-citizens-captured-in-ukraine/" target="_blank">a long war” in Ukraine</a> — and outlined a plan for how countries can help. After visiting Kyiv, Mr Johnson said that the <a href="https://www.thenationalnews.com/world/uk-news/2022/06/17/boris-johnson-pledges-training-for-10000-ukrainian-troops-during-surprise-kyiv-visit/" target="_blank">Russian invasion is “entering a new phase” </a>and, if its military was successful, then Russian President Vladimir Putin “would not stop at dismembering <a href="https://www.thenationalnews.com/tags/ukraine/" target="_blank">Ukraine</a>”. “I am afraid that we need to steel ourselves for a long war, as Putin resorts to a campaign of attrition, trying to grind down Ukraine by sheer brutality,” Mr Johnson wrote in <i>The Times</i>. “The UK and our friends must respond by ensuring that Ukraine has the strategic endurance to survive and eventually prevail.” “Everything will depend on whether Ukraine can strengthen its ability to defend its soil faster than Russia can renew its capacity to attack,” he added. “Our task is to enlist time on Ukraine's side.” He warned that if Russia is successful in securing territory in Ukraine, “no nation anywhere would be safe” because “every dictator would feel emboldened to pursue their own ambitions by force”. The prime minister’s four-point plan for Ukraine is: Nato secretary general Jens Stoltenberg said the supply of state-of-the-art weaponry to Ukrainian troops would increase the chance of liberating the eastern Donbas region from Russian control. "We must prepare for the fact that it could take years," Mr Stoltenberg said. "We must not let up in supporting Ukraine — even if the costs are high — not only [by providing] military support, but also because of rising energy and food prices." Mr Johnson, who met President Volodymyr Zelenskyy in Kyiv on Friday, said that the UK would aim to work with allies to train up to 10,000 soldiers every 120 days to support Ukraine. Speaking with reporters at RAF Brize Norton in Oxfordshire on his return, he stressed the need to demonstrate support for Ukraine when its people were “suffering terribly”, particularly in the Donbas. He said Ukrainians should be supported to regain territory lost this year. But he stopped short of calling for the recovery of all the lands Ukraine had lost since 2014 — including Crimea — something British Foreign Secretary Liz Truss has previously called for. Mr Johnson’s visit came one day after a joint trip to the Ukrainian capital by French President Emmanuel Macron, German Chancellor Olaf Scholz, and Italian Prime Minister Mario Draghi.