United States President Donald Trump has backpedaled on a planned "lock and loaded" attack on Iran after claiming Tehran and other Middle Eastern countries had sought it and that the perimeters of a deal have been agreed to, including the Strait of Hormuz reopening.

Trump's latest walk back came after a phone call with Saudi Crown Prince Mohammed bin Salman bin Abdulaziz Al Saud late Saturday amid a wave of warnings from Iran that vowed a decisive response and retaliation that would go beyond the region.

According to an update from the Saudi Press Agency on Sunday, the Saudi Crown Prince "stressed the need to prioritize dialogue to reduce escalation" in his phone call with Trump.

He also stressed the importance of making every possible effort to achieve calm that paves the way for diplomatic solutions, preserves the region's security and stability, and prevents a wider conflict whose repercussions would affect regional and international security and stability.

In a social media post, Trump had said the US "is locked and loaded and ready to go against the Islamic Republic of Iran, at levels of Military Terror, Strength, and Power not seen since World War II".