Ukrainian President Volodymyr Zelenskyy said he was thankful to U.S. President Joe Biden for the additional military aid but said he would not say specifically what the new package included because he didn’t want to tip off Russia. “This is our defense,” he said in his nighttime video address to the nation. “When the enemy doesn’t know what to expect from us. As they didn’t know what awaited them after Feb. 24,” the day Russia invaded. “They didn’t know what we had for defense or how we prepared to meet the blow.” READ: Hundreds feared trapped in Ukraine theater hit by airstrike Zelenskyy said Russia expected to find Ukraine much as it did in 2014, when it seized Crimea without a fight and backed separatists as they took control of the eastern Donbas region. But Ukraine is now a different country, with much stronger defenses, he said. He said it also was not the time to reveal Ukraine’s tactics in the ongoing negotiations with Russia. “Working more in silence than on television, radio or on Facebook,” Zelenskyy said. “I consider it the right way.” READ: Ukraine mayor, 9 Russian conscripts released