As reported by Censor.NET, this was announced by MP Boryslav Bereza on his Facebook page.
"I wonder if the Defense Ministry lies all the time or just today. They used to lie before, and we have good reasons to believe NATO. My words can be confirmed by each member of Ukraine's delegation to NATO. Yurii Bereza, Andrii Teteruk, Volodymyr Parasiuk, Ivanna Klympush-Tsintsadze, Viktor Chumak - it's time to fight irresponsibility of Ukrainian officials," he wrote.
Below is a print screen of Defense Ministry's disproof of Bereza's initial statement regarding their refusal to cooperate with NATO.
"Following the accusations, the Ministry of Defense of Ukraine officially announces that MP Boryslav Bereza's information is fake and based on untrue facts.