Kyiv and Washington are discussing new steps to help bolster Ukraine’s air defense systems, Ukrainian President Volodymyr Zelenskyy said Saturday, in the aftermath of a massive Russian attack on the country’s energy system.

“I had a call with U.S. President Donald Trump — a very positive and productive one,” Zelenskyy said on X Saturday afternoon. “We discussed opportunities to bolster our air defense, as well as concrete agreements that we are working on to ensure this.”

The announcement come a day after Moscow launched a fresh assault on Ukraine’s energy infrastructure, unleashing more than 450 drones and 30 missiles in an attack that left at least 20 people injured and parts of the country without electricity. Power has since been restored to 800,000 people in Kyiv, Ukrainian authorities said.

It marks the latest episode in a broader shift by the Trump administration on Ukraine, as the U.S. president grows increasingly impatient with Russian President Vladimir Putin and frustrated with stalling efforts to end Moscow’s all-out war on Ukraine.

In the past month, Trump has approved the first military support package of his term to Kyiv under the NATO-funded Prioritized Ukraine Requirements List initiative. He has also teased the idea of supplying Kyiv with long-range Tomahawk missiles, and said Ukraine could “win all of [the country] back in its original form.”

Tomahawk missiles, which Kyiv could use to strike targets up to 2,500 kilometers inside Russia, reportedly featured in the leaders’ latest conversation on Saturday.

The discussion comes as Kyiv gears up for a challenging winter, as Moscow steps up its air attacks and deploys new software to dodge Ukraine’s air defense systems, while the country races to secure enough energy supplies in the months to come.

Ukraine’s military chief Oleksandr Syrskyi on Saturday said the country’s air defenses were about 74 percent effective. But Russia has increased its air strikes by 1.3 times over the past month, he added, meaning Kyiv “must make further efforts to protect rear-area energy facilities, critical infrastructure, and logistics.”

Recent Russian attacks have destroyed more than 50 percent of Ukraine’s natural gas production capacity. In response, Ukrainian Energy Minister Svitlana Hrynchuk last week said Kyiv would have to ramp up its gas imports by 30 percent this winter.