Iran's Revolutionary Guards claimed Thursday they shot down a US drone in the southern province of Hormozgan.
State news agency IRNA quoted the Guard's news website, Sepah News, as saying that the Islamic country's military force targeted the "RQ-4 Global Hawk" when it entered Iran's airspace "near the Kouhmobarak district in the south."
Responding swiftly to the Iranian claim, the US military said it did not violate Iranian airspace on Wednesday.
"No US aircraft were operating in Iranian airspace today," said Navy Captain Bill Urban, a spokesman for the US military's Central Command.
The US last week did confirm a previous Iranian attempt to shoot down one of its drones.
Tensions between Washington and Tehran have escalated over the past month, with the US accusing Iran of continued malign activity and unspecified threats against the United States and its allies. Washington has also increased its military presence in the region.
The US accused Iran last week of attacking Japanese and Norwegian flagged tankers near the strategic Strait of Hormuz. Washington released video and pictures purporting to show a Revolutionary Guard boat removing an unexploded limpet mine.
Iranian officials rejected US claims that Tehran was behind the blasts.
German Chancellor Angela Merkel said Tuesday there was "strong evidence" Iran was behind the twin tanker attacks.
Deal under threat
US President Donald Trump withdrew from the 2015 Iranian nuclear deal last year and reimposed harsh sanctions on Tehran that have hit oil exports and sent its economy into freefall.
On Monday, Iran warned that it would soon surpass the amount of enriched uranium allowed under the international deal, ratcheting up pressure on European signatories to save the accord.
Iran's atomic energy agency also raised the prospect of increasing enrichment levels beyond the 3.67% level allowed under the deal for peaceful purposes.