The Ukrainian president, Volodymyr Zelenskyy, has called for face-to-face negotiations in a public letter addressed directly to the Russian president, Vladimir Putin.The letter, the first public letter Zelenskyy has written directly to Putin since Russia launched its full-scale invasion in 2022, was a sweeping criticism of the Russian leader’s 26 years in power.Zelenskyy acknowledged shifting US priorities, saying it would be wrong to simply wait for the Trump administration to return its attention to ending the Ukraine war while it remained heavily focused on the Iran war.“I am proposing a meeting,” Zelenskyy wrote.He appeared to be trying to seize a pivotal moment in the war as Ukraine has begun to regain some battlefield leverage, largely through improved long-range strike capabilities that have complicated Russia’s advances. At the same time, Moscow has intensified its deadly aerial campaign across Ukraine, seeking to exploit Kyiv’s shortages and continued vulnerability to ballistic missile attacks.Putin said on Thursday that Russia would strengthen its air defences to counter recent Ukrainian drone attacks, which have reached deep inside his country and cast a cloud over his showcase economic forum in his home town of St Petersburg.Vladimir Putin said Russia needed to improve and strengthen its air defence system, ‘and we will do that’. Photograph: Sergey Bobylev/Sputnik/Kremlin Pool/EPASpeaking during a meeting with heads of international news agencies, Putin acknowledged the damage from Ukrainian drone attacks. “To our regret, some of them break through,” Putin said of the strikes. “Russia has an air defence system, we need to improve it, strengthen it, and we will do that.”The wide-ranging media session came on the sidelines of the St Petersburg International Economic Forum, Putin’s annual showcase for investment. Hours before the forum opened on Wednesday, a Ukrainian drone attack set ablaze an oil terminal in the city and also hit a nearby naval base.Putin also said Russia was open for a compromise on Ukraine in line with the understandings reached at his summit with Donald Trump in Anchorage, Alaska, and Ukraine needed to accept them to make a deal to end the conflict, now in its fifth year.Trump said on Thursday it would be “great” for Zelenskyy to meet Putin – but said both sides had to make compromises, without explaining further.“I’m glad that they’re maybe talking about meeting. I think we had a lot to do with it,” Trump told reporters in the Oval Office. “I think it would be great if they met. They should – get it done.“They’re going to both make compromises, I suggested those compromises, and you know, we’ve had a lot to do with it.”Ukrainian drones hit oil terminal infrastructure in St Petersburg on Wednesday. Photograph: ReutersIn his letter, Zelenskyy said the proposed talks could be hosted by a neutral third country, ruling out Moscow and Kyiv as venues, and suggested Switzerland, Turkey or Arab states as possible hosts for negotiations.“It is leaders who resolve the key issues. That has always been the case, and it always will be,” he wrote. “I propose to set a clear date for such a meeting.”He said Ukrainian intelligence indicated Russia was considering plans to prolong the war into 2027 and 2028, while increasingly relying on ballistic missile strikes to achieve what its ground campaign had failed to accomplish.Zelenskyy also accused Moscow of seeking to draw Belarus deeper into the conflict and of attempting to destabilise the situation around Transnistria, the breakaway Moldovan region backed by Russia.The Ukrainian leader argued that Russia was increasingly feeling the costs of the war, pointing to drone attacks deep inside Russian territory, economic strain, fuel shortages, rising prices, and the necessity of more military mobilisation.Zelenskyy claimed Russia had suffered more than 30,000 soldiers killed or seriously wounded in May alone, saying Ukraine had “video confirmation” of the battlefield losses and that such casualty levels had been sustained month after month.He said Ukraine also continued to suffer painful losses despite what he described as a favourable casualty ratio.Zelenskyy said Ukraine was prepared to implement a full ceasefire for the duration of negotiations and proposed an all-for-all prisoner exchange as a first step toward ending the conflict. He also called for the return of civilians and children taken from Ukraine during the war.“The world has not grown tired of Ukraine, as you long hoped it would. But there is growing fatigue with Russia,” Zelenskyy said, addressing Putin.