Ukrainian President Volodymyr Zelensky on Sunday said Ukraine should get ready for winter, fearing Russia will pick up its campaign of systematic strikes on power facilities.
Repeated attacks by Moscow's forces last year targeted Ukraine's energy grid, leaving thousands without heating or electricity in freezing temperatures for long periods.
"We must be prepared for the possibility that the enemy may increase the number of drone or missile strikes on our infrastructure," Zelensky said in his daily address.
"All our attention should be focused on defence... on everything that Ukraine can do to make it easier for our people to get through this winter and to increase the capabilities of our troops."
Kyiv has already said it was bolstering defences to protect key infrastructure.
"The Ukrainian air shield is already stronger than last year," Zelensky said.
Ukraine has received significant air defence systems from the West, including the U.S.-made Patriot.
"Unfortunately, (the air shield) does not yet fully protect the entire territory. And we are working to make it even better."
Zelensky called on the international community to echo his appeal.
His statement was published soon after presidential aide Andriy Yermak said he arrived in the United States as part of a delegation that will discuss support including "strengthening Ukraine's defence".
