US President Donald Trump has been given military options for a strike on Iran amid continuing protests in Iranian cities, but has not made a final decision, according to reports in two leading American newspapers, The New York Times and Wall Street Journal.

In a defiant response, Iran’s National Defence Council warned that Tehran would not necessarily limit itself to retaliatory responses if it perceives concrete threats to its security.

In a statement published by Iranian media, the Council said that Iran’s “security, independence, and territorial integrity” constitute an “uncrossable redline,” and that any encroachment on those interests would be met with an “appropriate, targeted, and decisive response.”

“Within the framework of legitimate self-defence, the Islamic Republic of Iran does not consider itself limited to reacting after the action and considers objective signs of threat to be part of the security equation,” the statement said.

Meanwhile, Trump also posted on social media that “Iran is looking at FREEDOM, perhaps like never before. The USA stands ready to help!!!”

The US State Department separately warned, “Do not play games with President Trump. When he says he’ll do something, he means it.”

The New York Times report says Trump is seriously considering authorising a strike in response to the Iranian regime’s efforts to suppress demonstrations, and the options presented to him include non-military sites in Tehran. But no further details were given.

As protests escalate, Supreme Leader Ayatollah Ali Khamenei signalled a coming clampdown, despite US warnings.

Iran’s attorney general, Mohammad Movahedi Azad, warned that anyone taking part in protests or “helping rioters” will be considered an “enemy of God,” a death-penalty charge.

“Proceedings must be conducted without leniency, compassion or indulgence,” he said.

State television and news agencies have shown video of purported protesters shooting at security forces with firearms, according to reports.