The White House on Monday said it was not involved in a power outage incident at an Iranian nuclear site and declined comment on Tehran's accusing Israel of sabotaging the Natanz facility, Reuters reported.
"The US was not involved in any manner," White House press secretary Jen Psaki said in response to questions. "We have nothing to add on speculation about the causes or the impacts."
Iran vowed revenge for what it described as an act of "nuclear terrorism" that caused an electricity outage in one of the production halls at the uranium enrichment plant.
Israel fiercely opposes Tehran's 2015 nuclear deal with major powers, an accord that Iran and the new administration of President Joe Biden are engaged in trying to revive after then-US President Donald Trump abandoned it three years ago.
Multiple Israeli media outlets quoted unnamed intelligence sources as saying Israel's Mossad spy service carried out a successful sabotage operation at the underground complex.
Israel, whose existence Iran does not recognise, has not formally commented on the incident.
Iran and the global powers described as "constructive" talks last week to salvage the nuclear deal, which has unraveled as Iran has breached its limits on sensitive uranium enrichment since Trump reimposed harsh sanctions on Tehran.
Talks are expected to resume on Wednesday in Vienna, and Psaki said she expected them to be "difficult and long."
"We have not been given any indication about a change in participation," by Iran, she said.