The head of Iran's nuclear agency is warning the United States against undermining the 2015 nuclear deal, saying international nonproliferation efforts as well as Washington's global standing would suffer, Independent reported.

Iranian nuclear chief Ali Akbar Salehi told an international conference on enhancing nuclear safety that Washington’s recent “delusionary negative postures do not augur well” for keeping the deal intact.

He said Iran didn’t want to see the deal unravel but that “much more is at stake for the entire international community than the national interests of Iran.”

US President Donald Trump is set to deliver a speech on Iran this week in which he is expected to decline to certify Iran’s compliance in the landmark 2015 agreement, referring it to Congress, and perhaps targeting the country’s paramilitary Revolutionary Guard with new sanctions.

Salehi praised the progress that had been made since the 2015 deal, saying nonproliferation and disarmament efforts had benefited worldwide. He called it “simply too precious to be allowed to be undermined or weakened.”

“The failure of the nuclear deal will undermine the political credibility and international stature of the US in this tumultuous political environment,” Salhehi warned.

He concluded that he hoped “common sense shall prevail.”