Ten years of war. Not a single day did this document work," Zelensky said."And because of this, everyone in the world will now know that a mere signature — by any state — or any assurances or promises are not enough for security."According to the Budapest Memorandum, the signatory countries — the U.K., Russia, and the U.S. — pledged to be guarantors of Ukraine's independence, as well as sovereignty, and refrained from using weapons or economic pressure against Ukraine. In exchange, Ukraine renounced its nuclear status.Zelensky added that effective guarantees are needed for Ukraine's security, namely "real alliances and a real security foundation within the country," as well as "weapons that enable defense and deterrence of the enemy."The president also called for unity, saying it helps to overcome "even the most challenging moments.