Iranian Foreign Minister Javad Zarif has condemned US President Donald Trump over his threats to walk away from a landmark nuclear deal between Tehran and Western powers signed in 2015.

The lead negotiator for the Iranian side told Al Jazeera that the US leader's remarks would not "help peace and security in the region" and would harm the long-term interests of the United States.

Trump has repeatedly described the nuclear agreement, which was negotiated by the Obama administration and enshrined under United Nations Security Council Resolution 2231, as "the worst deal ever".

"I think it is an ill-informed statement, because certainly, any deal would not be a perfect deal for all sides; it has to be less than perfect so all sides can live with it," Zarif said, warning that the international community could never trust the US again if it violated the deal.

READ MORE: Donald Trump denounces Iran over nuclear deal

Zarif said any breaches of the deal by the US would result in Iran's partial or complete withdrawal from the agreement, noting that Tehran would be undeterred by threats of sanctions.

"The nuclear deal is the result of 10 years of posturing and two years of negotiations. Unfortunately, this administration is going back to posturing," he said. "They [US leaders] have immunised us to US sanctions. From a global perspective, it would seem the United States is addicted to sanctions."

Dialogue with Saudi Arabia

Zarif also condemned Iran's regional rivals, Israel and Saudi Arabia, for their role in urging the US to renege on the agreement.

The deal was a source of contention between the Obama administration on one side, and Riyadh and Tel Aviv on the other.

However, since Trump's election, leaders from both states have welcomed the hardline approach adopted by the US.

Addressing his country's strained relationship with Saudi Arabia, Zarif said there was a willingness in Tehran to initiate a rapprochement.

READ MORE: Is the time right for Saudi-Iran rapprochement?

"We are willing to talk to Saudi Arabia about our difference ... We do not believe that Iran and Saudi Arabia should have the type of relationship they have right now," he said.

That openness did not stop him from condemning Saudi Arabia over its purported support of rebel groups in Syria and Yemen, as well as its treatment of Qatar.

"We believe the posture in the Persian Gulf by Saudi Arabia is not a positive one, [like] the policies they pursue against Qatar," Zarif said, adding that Saudi Arabia was using claims of Iranian expansionism to justify its own attempts to exert influence in the region.

"The concepts they are using to muddy the waters, policies that have brought unfortunate disastrous consequences for our region, cannot be justified by these smokescreens of exporting revolutions."