Washington, April 13 : The White House said that the United States was not involved in a recent attack on Iran's Natanz nuclear facility. "We, of course, have seen the reports of the incident at the Natanz enrichment facility. The US was not involved in any manner. We have nothing to add on speculation about the causes or the impacts," White House Press Secretary Jen Psaki told reporters during the daily briefing on Monday, Xinhua news agency reported. Psaki said that the United States is focused on discussions scheduled this Wednesday in Vienna to revive the Iran nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA). "We expect them to be difficult and long," she said. "We have not been given any indication about a change in participation for these discussions." US Secretary of Defence Lloyd Austin on the same day told reporters travelling with him to Israel that he was very supportive of US efforts to engage Iran in diplomacy over the JCPOA, saying these efforts will continue. The Atomic Energy Organization of Iran (AEOI) said Sunday that an accident took place in a part of the electricity distribution network of the Natanz nuclear facility in the morning. The AEOI head Ali Akbar Saleh described the incident as an act of "nuclear terrorism." Iranian Foreign Minister Mohammad Javad Zarif on Monday blamed Israel for the incident in Natanz and vowed revenge on Israel, official news agency IRNA reported. Israeli Prime Minister Benjamin Netanyahu Monday said in a press conference alongside Austin that Israel would never allow Iran to obtain nuclear weapons. Austin did not mention Iran in his statement but said that the United States and Israel would "maintain close cooperation." /IANS