Ukraine said Wednesday Russia launched 14 drones and a cruise missile as part of its latest attacks.
The Ukrainian Air Force said its air defenses downed all of the drones, which were directed at parts of central, southeastern and western Ukraine.
There were no immediate reports of major damage or casualties.
The Ukrainian military also said the Russian X-22 missile fell into a field in the Zaporizhzhia region without reaching its target.
Ukraine identified the Russian drones as being Shahed drones made by Iran, and the latest attacks followed warnings by the United States that Iran could provide Russia with ballistic missiles to use in its war in Ukraine.
"In return for that support, Russia has been offering Tehran unprecedented defense cooperation, including on missiles, electronics and air defense," National Security Council spokesperson John Kirby told reporters Tuesday.
Kirby said that in addition to drones, Iran has already provided Russia with guided aerial bombs and artillery ammunition for use in Ukraine.