US President Donald Trump said Iran has reached out to negotiate as his administration weighs “very strong” actions following a deadly crackdown on protesters that rights groups say has killed hundreds.

Speaking to reporters aboard Air Force One on Sunday, Trump said Iran appears to be crossing his previously stated red line on the killing of protesters. “They’re starting to, it looks like,” he said, adding that the military is reviewing options and a determination will be made soon.

Trump stressed that violence against civilians is his biggest concern and said he is receiving hourly briefings on developments in Iran.

Iran proposes talks, Trump claims

Against the backdrop of rising tensions -- and after the US ousted Venezuelan leader Nicolás Maduro -- Trump claimed Tehran has proposed negotiations. “I think they’re tired of being beat up by the United States,” he said. “Iran wants to negotiate.”

Trump repeated that Iran’s leaders called him on Saturday and want talks, even as Washington weighs punitive measures.

Death toll disputed amid internet blackout

US-based Human Rights Activists News Agency (HRANA) said at least 538 people have been killed, including 490 protesters, and more than 10,600 arrested. Another monitor, Iran Human Rights, reported at least 192 protester deaths.

Figures vary due to restricted access and a near-total internet blackout imposed on Thursday. The Iranian government has not released official casualty numbers, and independent verification has been impossible.

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The unrest -- Iran’s most significant in years -- began in late December after a sharp currency slide and worsening economic conditions. Demonstrations quickly broadened to calls for political reform and the government’s downfall.

Authorities arrested key protest figures, police chief Ahmad-Reza Radan said, warning of legal punishment without specifying numbers. Iran’s attorney general previously said protesters or those aiding them could face charges of being an “enemy of God,” a capital offense.

Trump threatens intervention; Tehran warns of retaliation

Trump reiterated his threat to intervene if lethal force continues. “Iran is looking at FREEDOM, perhaps like never before. The USA stands ready to help!!!” he posted on social media.

Iran’s parliamentary speaker Mohammad Baqer Qalibaf warned that any US attack would make Israel and US bases and ships “legitimate targets,” vowing retaliation without limitation.

US officials told CNN that Trump has been briefed on a range of responses, including military strikes focused on security services suppressing protests, cyber operations, expanded sanctions, and online support for anti-government sources.

Officials cautioned that strikes could backfire by rallying public support for Tehran or triggering retaliation. The New York Times first reported the briefings.

Starlink and sanctions short of war

The administration is also considering non-kinetic measures. These include cyber actions against regime targets, sanctions on regime figures or sectors such as energy and banking, and boosting internet access through Starlink to help protesters bypass the blackout.

Also Read: Deaths from Iran protests reach 'more than 500'

Trump said he would likely call Elon Musk, whose company provides Starlink—an approach previously explored during protests in 2022.

Iranian leaders blame foreign enemies

Iran’s president Masoud Pezeshkian accused the US and Israel of escalating unrest by importing “terrorists,” urging citizens to join a “national resistance march” on Monday.

Meanwhile, exiled opposition figure Reza Pahlavi called on security forces and state employees to side with protesters rather than the authorities.

Israeli officials said they are on high alert for any US intervention, remaining publicly quiet to avoid Tehran portraying protests as foreign-backed. Israel Defense Forces said it is monitoring developments and maintaining defensive readiness.

US Secretary of State Marco Rubio discussed the situation with Israeli Prime Minister Benjamin Netanyahu, alongside regional issues including Syria and Gaza.

Decision pending as risks mount

Trump has not made a final decision and says options under review do not include boots on the ground. More formal briefings are expected this week, including a senior national security meeting.

Asked how Washington would respond if Iran struck US bases, Trump warned: “We will hit them at levels that they’ve never been hit before.”