Zelensky, speaking in a speech taped from Kyiv to the UN General Assembly, attacked Russia’s recent escalation, which he said showed President Vladimir Putin was not serious about any potential talks to end the conflict. “Russia is afraid of real negotiations and does not want to fulfill any of them [its] international obligations,” Zelensky said. “He lies to everyone.” Earlier on Wednesday, Putin ordered the mobilization of army reserves to support Moscow’s troubled campaign in Ukraine, warning he would use Russia’s nuclear arsenal if its “territorial integrity is threatened”. “This is not a bluff,” he added. The warning, which caused immediate alarm in Washington and around the world, came as Putin claimed the West wanted to “weaken, divide and destroy Russia” and press ahead with plans to annex parts of Ukrainian territory. In his address to the UN, Zelensky demanded retaliation from Western countries for Russia’s actions, including the lifting of its veto in the UN Security Council. “A crime has been committed against Ukraine and we demand fair punishment,” he said. US President Joe Biden also criticized Putin’s “blatant nuclear threats against Europe [and] reckless disregard for the responsibilities of a non-proliferation regime,” attacking the referendum and mobilization plans in his speech to the UN on Wednesday as “outrageous acts”. Biden added: “This war is about eliminating Ukraine’s right to exist as a state, plain and simple. . . That should make your blood run cold.” Moscow announced the “partial mobilization” of 300,000 reservists ahead of votes in four occupied regions of Ukraine on the question of joining Russia. Western officials estimate that between 150,000 and 190,000 Russian forces are currently on the ground in Ukraine. The results of the “referendums,” which begin Friday in the Russian-controlled regions of Donetsk, Luhansk, Kherson and Zaporizhia, are effectively a foregone conclusion, given that the Kremlin is in charge of the votes.

Zelensky promised that Ukraine would take back “all of its territory” and asked for more weapons from the US and other Western countries to help it. He also urged the US and others to declare Russia a state sponsor of terror or take other political actions to send a strong message of Russia’s isolation on the world stage. “We must finally recognize Russia as a state sponsor of terrorists at all levels in all countries,” he said. The Biden administration has opposed such a step, saying it could hurt humanitarian aid efforts and interfere with potential peace talks. The US and other Western powers will denounce Russia at Thursday’s UN Security Council meeting on Ukraine, which Russian Foreign Minister Sergei Lavrov is expected to attend. The diplomats are preparing for a tense confrontation. Also on Wednesday, Russia freed two US veterans and five British citizens in a prisoner swap with Ukraine brokered by Saudi Arabia, according to US and British officials.