DUBAI, United Arab Emirates (AP) — Israel attacked a key petrochemical plant at Iran’s massive South Pars natural gas field and killed a top Revolutionary Guard commander, putting into question the negotiations aimed at getting the U.S. and Tehran to reach a ceasefire.

Israel’s Defense Minister Israel Katz confirmed what he called “a powerful strike on the largest petrochemical facility in Iran” that’s responsible for half of the country’s petrochemical production. Israel’s military spokesperson, Lt. Col. Nadav Shoshani, said there would be “no immunity” for Iran as talks progress.

The gas field shared with Qatar is the world’s largest and sits under the waters of the Persian Gulf.

The White House did not immediately respond when asked about the strike. After Israel’s attack in March on South Pars, Trump said Israel would not attack it again but warned that if Iran continued striking Qatar’s energy infrastructure, the United States would retaliate and “massively blow up the entirety” of the field.

Trump’s deadline for Tehran to reopen the Strait of Hormuz looms while mediators scramble to get the U.S. and Iran to agree to a new ceasefire proposal.