Tehran: Iranian officials on Wednesday dismissed as "false and baseless" claims by US President Donald Trump that the Islamic Republic had requested a ceasefire to end the monthlong conflict.

Foreign Ministry spokesman Esmail Baghaei issued the rebuttal shortly after Trump asserted on social media that Tehran’s leadership was seeking a truce. The denial marks a sharp diplomatic breakdown as the April 6 deadline set by Washington for the reopening of the Strait of Hormuz approaches.

Separately, Iran's paramilitary Revolutionary Guard released a defiant statement asserting its absolute authority over the world’s most critical energy transit route. The elite military branch stated that the Strait of Hormuz "is firmly and decisively under the control" of its forces.

"This strait will not be opened to the enemies of this nation through the ridiculous spectacle by the president of the United States," the Revolutionary Guard added.

The conflicting narratives from Washington and Tehran come amid a surge in regional hostilities. While Trump suggested a diplomatic overture was underway, the Revolutionary Guard’s rhetoric indicates a hardening of the blockade that has paralysed global oil shipping.

The IRGC statement directly challenged the 15-point peace plan previously proposed by the United States, which includes a demand for the immediate and unconditional reopening of the waterway.

With inputs from AP