President Volodymyr Zelensky has emphasized the need for robust security assurances from allies to prevent Russia from regrouping for another attack."In the long term, the only credible security guarantee is Article 5 of the Washington Treaty—so NATO membership essentially," Valtonen said in an interview with Reuters during her visit to Kyiv, referencing the alliance's collective defense clause. "And we are supporting Ukraine's NATO membership further down the line and hopefully not in (the) too-distant future."Ukraine has strongly advocated for an invitation to join NATO, but resistance from key member states persists as the all-out war nears its three-year mark, with Ukrainian forces continuing to face challenges in pushing back Russian offensives.Trump, who has expressed skepticism about U.S. aid to Ukraine, said on Jan.