Israel has raised its security alert amid concern that the United States could intervene in Iran, where authorities are facing the largest anti-government protests in years, according to three Israeli sources familiar with the matter, Reuters reported.

President Donald Trump has repeatedly warned Iran’s leadership in recent days against using force to suppress demonstrators and has openly floated the prospect of U.S. involvement.

Iran Israel intervention

Speaking on Saturday, Trump said Washington stood “ready to help.” Israeli sources who attended security consultations over the weekend said Israel was closely monitoring developments but declined to specify what the heightened alert entailed.

The concerns come just weeks after Israel and Iran fought a 12-day war in June, during which the United States joined Israel in launching airstrikes.

According to an Israeli source present for the discussion, Prime Minister Benjamin Netanyahu and U.S. Secretary of State Marco Rubio spoke by phone on Saturday and addressed the possibility of American intervention in Iran. A U.S. official confirmed the call took place but did not disclose its contents.

Iran Israel intervention

Despite the unrest in Iran, Israel has not indicated that it intends to intervene directly. Tensions between the two long-standing adversaries remain high, driven by Israeli concerns over Iran’s nuclear ambitions and ballistic missile program.

In an interview with The Economist published on Friday, Netanyahu warned that Iran would face severe consequences if it were to attack Israel, while suggesting that developments inside Iran, including the ongoing protests, should be closely watched.