- Marco Rubio said regime change in Iran is more complex than in Venezuela
- No clear successor would emerge if Iran's Supreme Leader is removed, Rubio said
- Trump warned Iran of military action if nuclear talks fail
Amid US President Donald Trump's renewed warning to Tehran over its nuclear programme, America's Secretary of State Marco Rubio weighed in on the question of who would take over Iran's leadership if the supreme leader, Ayatollah Ali Khamenei, were removed. Addressing the Senate committee, Rubio acknowledged that forcing regime change in Iran would be much more complicated than it was in Venezuela, where the US forced the ouster of President Nicolas Maduro.
"This is not a frozen dinner, where you put it in a microwave and in two and a half minutes it comes out ready to eat. These are complex things," Rubio said, adding that "no one knows" who would take over if Iran's supreme leader were removed from power.
"I don't think anyone can give you a simple answer to what happens next in Iran if the Supreme Leader and the regime were to fall," he said.
Rubio's remarks came after Trump escalated tensions with Iran, issuing a renewed and stark warning to Tehran over its nuclear programme and threatening military action if negotiations fail to produce an agreement. Responding to Trump's threats, Iran has said that its forces would respond immediately and forcefully to any US military operation.
Rubio also addressed Tehran's warning and said that the United States could, "if necessary, preemptively prevent the attack against thousands of American servicemen and other facilities in the region and our allies," but added that he hoped "it wouldn't come to that."
US-Iran Tensions
In a post on social media platform Truth Social, Trump on Wednesday said a large US naval force, described as a "massive armada" led by the aircraft carrier USS Abraham Lincoln, was moving toward Iran. He expressed urgency for Iran to return to the negotiating table and urged Tehran to reach an agreement that would bar nuclear weapons development.
"Hopefully Iran will quickly 'Come to the Table' and negotiate a fair and equitable deal – NO NUCLEAR WEAPONS," Trump wrote, warning that "time is running out" and that if Iran does not comply, the next attack "will be far worse" than prior strikes.
The president's latest statement emphasised that military pressure remains an option if diplomacy stalls and comes against a backdrop of mounting regional strain and divergent positions on diplomacy and defence. His hardened language also reflects a shift from earlier US rhetoric focused primarily on human rights concerns in Iran.
In recent months, Tehran has faced international criticism for its crackdown on domestic protests, but the White House rhetoric increasingly places the nuclear issue at the centre of US strategic priorities.
Iran's leadership rejected the notion that talks could proceed under the shadow of military threats. According to state media, Iranian Foreign Minister Seyed Abbas Araghchi said, "There can be no negotiations in an atmosphere of threats," and criticised Washington's pressure tactics as ineffective and counterproductive.
The Iranian response also conveyed warnings of strong retaliation in the event of US military action. Some Iranian officials framed any attack as the start of a broader conflict, with potential responses targeting US interests and regional partners.
As of now, neither side has indicated a willingness to step back from its position. Washington continues to press for a deal ending Iran's nuclear weapons ambitions, while Tehran maintains its right to peaceful nuclear activities and insists that negotiations occur without threats.
In June 2025, American forces struck multiple Iranian nuclear facilities in coordination with Israel, an operation that Washington said significantly set back Tehran's nuclear capabilities.
