The White House said Monday that U.S. President Donald Trump is open to exploring diplomatic engagement with Iran.

Spokesperson Karoline Leavitt said Trump is "unafraid" to follow through on his threats to use military force on Iranian targets if demonstrators are attacked by security forces, but said his preference is to pursue diplomacy with Tehran.

"One thing President Trump is very good at is always keeping all of his options on the table. And airstrikes would be one of the many, many options that are on the table for the commander-in-chief, diplomacy is always the first option for the president," she told reporters at the White House.

"What you're hearing publicly from the Iranian regime is quite differently from the messages the administration is receiving privately. I think the President has an interest in exploring those messages. However, with that said, the president has shown he's unafraid to use military options if and when he deems necessary, and nobody knows that better than Iran," added Leavitt.

Earlier in the day, protests were held in several areas across Iran to show support for the government as anti-government demonstrations entered their 16th day over worsening economic conditions in the country.