Iranian president hassan rouhani has warned that the us will face "historical remorse" if donald trump scraps the nuclear settlement with tehran.
Mr rouhani's comments come as america president comes to a decision whether to tug out of the deal by way of a 12 might also deadline.
Mr trump has strongly criticised the settlement, calling it "insane".
The 2015 deal - between iran, the us, china, russia, germany, france and the UK - lifted sanctions on iran in go back for curbs on its nuclear programme.
France, the UK and germany were attempting convince america president that the current deal is the satisfactory manner to stop iran growing nuclear weapons.
What's the iran nuclear deal?
Is iran's financial system better off since the nuclear deal?Could the deal disintegrate?
British foreign secretary boris johnson is traveling to washington on sunday to talk about the problem with white house officers.
The un also warned mr trump not to walk faraway from the deal.
But, he has threatened that the us will "withdraw" from the deal on 12 might also - the give up of a a hundred and twenty-day review length - unless congress and eu powers constant its "disastrous flaws".
Media captionwhat is the iran nuclear deal?
In feedback carried stay on iranian nation tv on sunday, president rouhani stated: "if the united states leaves the nuclear deal, this can entail historic remorse for it."He warned iran had "a plan to counter any choice trump may additionally take and we will confront it".
Iran insists its nuclear programme is totally peaceful and says it considers the deal non-renegotiable.
Last week, israel found out "mystery nuclear files" which it stated showed iran had run a mystery nuclear weapons programme, which became reportedly mothballed 15 years in the past.
Iran branded israeli top minister benjamin netanyahu a liar and said the documents he produced were a rehash of old allegations already treated through the worldwide atomic strength agency (iaea), the un's nuclear watchdog.
But us secretary of nation mike pompeo stated the files had been proper and confirmed the 2015 iran nuclear deal become "constructed on lies".
Mr trump is already sad that the present day deal handiest limits iran's nuclear sports for a set length and does not stop the improvement of ballistic missiles.
He also stated it had surpassed iran a $100bn (£72bn) providence that it used "as a slush fund for weapons, terror, and oppression" across the center east.
Media captiona timeline of what trump's said approximately the iran deal
At some stage in days of talks in washington, mr johnson will meet us vice-president mike pence, national security adviser john bolton and overseas coverage leaders in congress.
Earlier this month, he stated it changed into crucial to maintain the deal "while building on it with a view to take account of the valid worries of america".
