“We will not approve any agreement until we are certain that the rights of the Iranian people have been upheld,” Ghalibaf said in a video broadcast on state television.

He added that Iranian negotiators “neither trust the enemy’s words nor its promises”.

His remarks came as Iran and Washington continue to exchange proposals over a framework for a deal to end the war that broke out on Feb 28, engulfing the Middle East.

On Saturday, The New York Times and Axios media outlets reported that US President Donald Trump had sent back to Tehran a new framework to be considered by Iran with “tougher” terms.

It was not immediately clear what that entailed.

Iran views sanction relief and the release of its assets frozen in banks abroad as among its key rights to be ensured under any deal with the US.

Since the outbreak of the war, Iran has kept tight control over the strategic Strait of Hormuz, a vital global energy conduit, and sees oversight of shipping through the waterway as within its rights.