Senior officials in the US defense establishment have warned US President Donald Trump that the military needs more time to prepare for strikes against Iran, British outlet The Telegraph reported on Sunday.
This comes as protests escalated over recent days against the Islamic Republic regime.
Trump is reportedly contemplating military action, including being presented with a range of targets, including leaders of Iran's security services, which have been responsible for clamping down on protesters, the outlet noted.
However, regional commanders reportedly told officials that they have to "consolidate US military positions and prepare defenses" before Washington could carry out any strikes intense enough to trigger Iranian retaliation.
Trump threatened to "get involved" in the protests, which are threatening to topple the regime, warning that he would hit Iran "very, very hard, where it hurts," if pro-regime security forces keep killing protesters.
Trump has been briefed on options including striking non-military targets within the capital city of Tehran, or targeting elements of the Islamic Republic's security apparatus, The Telegraph reported.
Trump briefing on Iran options planned for Tuesday, WSJ reports
Trump is scheduled to be briefed by senior officials in his administration on Tuesday on specific options to respond to the protests in Iran, the Wall Street Journal reported on Sunday, citing US officials.
The meeting will be a discussion about possible next steps, including military strikes, deploying cyber weapons against Iranian military and civilian sites, placing more sanctions on Iran's government, and boosting anti-government sources online, the Journal reported.
The White House said it had no comment on the report.
Trump, who has repeatedly threatened to intervene in recent days, posted on social media on Saturday: "Iran is looking at FREEDOM, perhaps like never before. The USA stands ready to help!!!
Some US senators skeptical about military options for Iran
Meanwhile, some US lawmakers in both major parties questioned whether military action against Iran is the best approach for the United States as Iranian authorities face growing turmoil.
Trump, in recent days, has left open the possibility of American intervention in Iran, where the biggest anti-government protests in years have led to the Islamic Revolutionary Guards Corps blaming unrest on terrorists and vowing to safeguard the governing system.
But at least two US senators sounded notes of caution during interviews on TV networks’ Sunday morning programs.
"I don’t know that bombing Iran will have the effect that is intended,” Republican Senator Rand Paul said on ABC News’ "This Week" show.
Rather than undermining the regime, a military attack on Iran could rally the people against an outside enemy, Paul and Democratic Senator Mark Warner said.
Warner, appearing on "Fox News Sunday," warned that a military strike against Iran could risk uniting Iranians against the United States "in a way that the regime has not been able to." History shows the dangers of US intervention, said Warner, who argued that the US-backed 1953 overthrow of Iran's government set in motion a chain of events that gradually led to the rise of the country's Islamic regime in the late 1970s.
Iran has said it will target US military bases if the United States launches an attack. But Republican Senator Lindsey Graham, who has often touted a muscular approach to foreign policy, said Trump "needs to embolden the protesters and scare the hell out of the [Iranian] regime."
"If I were you, Mr. President, I would kill the leadership that are killing the people," Graham said on Fox News' "Sunday Morning Futures" show. "You’ve got to end this."
Reza Pahlavi, the US-based son of the Iranian shah who was ousted in 1979, said on Sunday he is prepared to return to Iran to lead a shift to a democratic government.
"I'm already planning on that," Pahlavi said on "Sunday Morning Futures." "My job is to lead this transition to make sure that no stone is left unturned, that in full transparency, people have an opportunity to elect their leaders freely and to decide their own future."
Reuters contributed to this report.