Iran is preparing for a sustained conflict and does not intend to accept the conditions being set by the United States and Israel, according to a report citing regional diplomatic sources.

An Arab diplomat involved in ongoing contacts between Tehran and Washington said Iranian leadership believes it can continue fighting for an extended period and ultimately end the war on terms more favorable to itself. The report was presented Monday morning on a news program on Israel’s Kan public broadcaster.

According to the diplomat, this assessment is not only being conveyed publicly but is also firmly held behind closed doors within Iran’s leadership. Officials in Tehran view the demands coming from Washington and Jerusalem as tantamount to surrender, and for that reason have not even responded to President Donald Trump’s reported 15-point proposal.

The same source said Iranian officials believe they have the capacity to withstand a prolonged military campaign while inflicting even greater damage on Israel, the United States, and other countries in the region.

As a result, diplomatic circles in the Middle East are increasingly pessimistic about the chances of de-escalation, with officials warning that only an extraordinary development is likely to prevent further escalation of the conflict.