Russia trying to stop meeting on peace and prolong war- Zelensky
Russian Foreign Minister Sergei Lavrov said Putin was ready to meet Ukraine's leader "when the agenda is ready for a summit and accused Zelensky of saying "no to everything".
Ukraine's President Volodymr Zelensky has accused Russia of "doing everything it can" to prevent a meeting with Vladimir Putin to try to end the war.
US President Donald Trump has sought to bring the two leaders together, but he said on Friday "that's like oil and vinegar... they don't get along too well".
Russian Foreign Minister Sergei Lavrov said Putin was ready to meet Ukraine's leader "when the agenda is ready for a summit, and this agenda is not ready at all", accusing Zelensky of saying "no to everything".
After an intensive week of diplomacy, in which Trump first met Putin in Alaska and then Zelensky with European leaders in Washington, the US president said the war was turning out to be the most difficult he had tried to stop.
Trump said after a call with the Russian leader on Monday that he had begun arrangements for a Putin-Zelensky summit that he would join afterwards.
Ukraine's president has backed the move, but he has sought security guarantees from Western allies to prevent any future Russian attack in the event of a peace deal: "Ukraine, unlike Russia, is not afraid of any meetings between leaders."
On a visit to Kyiv, Nato Secretary General Mark Rutte said Trump was aiming to "break the deadlock" and the alliance was working on robust security guarantees with the US and Europe to ensure Putin "will never ever try to attack Ukraine again".
Speaking alongside Rutte, Zelensky said he wanted Ukraine's security guarantees to reflect Nato's Article 5, which considers an attack on one member of the alliance an attack against all Nato members.
"This is the beginning of a big undertaking, and it is not easy, because guarantees consist of what our partners can give Ukraine, as well as what the Ukrainian army should be like, and where we can find opportunities for the army to maintain its strength," Zelensky said.
Rutte said the alliance was working with Ukraine to define the guarantees, explaining that they would focus on making Ukraine's military as strong as possible and involve Western security commitments. It was "too early to exactly say what will be the outcome", he added.
