Senior aide to President Volodymyr Zelenskyy suggested Ukraine is linked to a drone strike in Iran.
Ukraine has not officially confirmed any connection to Saturday's explosion.
By contrast, US officials suspect Israel is behind the strike, according to The New York Times.
A senior aide to President Volodymyr Zelenskyy on Saturday gloated over a drone strike on an Iranian weapons facility, hinting that the attack was made in connection with Russia's invasion of Ukraine.
Over the weekend, footage circulated online of a large explosion on the roof of a building in Isfahan, western Iran, prompting Mykhailo Polodyak to tweet: "[Ukraine flag] did warn you."
A Ukrainian-language version of Polodyak's tweet included a screenshot of his purported "warning," a December 24 tweet in which he called for the destruction of Iranian production facilities.
There has been no official confirmation from Ukraine that it was involved. Senior defense officials, who were not named, told The New York Times that it was their belief the attack in Isfahan was the work of Mossad, acting out of concern for Israel's security.
Israel's Ministry of Foreign Affairs declined to comment.
Polodyak's remarks have caused a diplomatic stir, with Iran's Ministry of Foreign Affairs summoning the Ukrainian charge d'affaires in Tehran on Monday in reaction to the comment, according to Iranian news agency Nour News.
The attack came around the same time as a large fire at an Iranian oil refinery, which Polodyak also referenced in his Sunday tweet. "Explosive night in Iran," he wrote.
Iranian state media called the strike a failure on Sunday, saying that it had shot down one drone and trapped two others in its defense system.
Iran's Ministry of Defense said the attack was made on a "defense equipment manufacturing complex."
Ukrainian defense outlet Defense Express, meanwhile, shared satellite imagery that suggested the damage was minimal.
In his tweet, Polodyak suggested the site was used for "drone and missile production." Insider was unable to immediately confirm this. However, if true, it would make it a site of key concern in Ukraine, which has accused Iran of supplying drones to Russia to attack Ukrainian cities.
Iran claims it only sent drones to Russia before Moscow's invasion of Ukraine last year. Russia also denies its military uses Iranian drones in Ukraine.
Isfahan is a major defense manufacturing center and home to a large military air base, according to CNBC.