Iranian foreign minister Mohammad Javad Zarif says the United States should meet its own obligations agreed in a landmark nuclear deal in 2015 rather than raising accusations against the Islamic Republic.
Zarif said in a tweet that the US should "fulfill its own commitments," in response to a comment from US Secretary of State Rex Tillerson.
Tillerson said in a letter to House of Representatives Speaker Paul Ryan, the top Republican in Congress, on Tuesday that Iran remained compliant with the 2015 deal, but there were concerns about its role as a state sponsor of terrorism.
His tough words matched those of US Defence Secretary Jim Mattis, who said in a visit to Saudi Arabia on Wednesday that Iran's destabilising influence would have to be overcome to end the conflict in Yemen.
President Donald Trump ordered the review to evaluate whether suspension of sanctions related to the nuclear deal was "vital to the national security interests of the United States", Tillerson said
Though there was no sign the Trump administration intended to walk away from the deal, Tillerson twice cautioned that if left unchecked Tehran could become a threat like North Korea, which is also under pressure over its nuclear ambitions.
He said the 2015 nuclear deal between Iran and six world powers failed "to achieve the objective of a non-nuclear Iran and only delays their goal of becoming a nuclear state."
In his tweet, Zarif also addressed Tillerson's terrorism charge: "Worn-out US accusations can't mask its admission of Iran's compliance w/ JCPOA."
Iran helped to create and continues to fund Hezbollah, the Lebanese military and political organisation which the United States has listed as a terrorist organisation.
Both Iran and Hezbollah are currently fighting in support of Syrian President Bashar al Assad's forces. Iran has also sent military advisers and fighters to neighbouring Iraq, where they are taking part in the Baghdad government's operations against Islamic State.
Iranian hardliners have regularly criticised Zarif and President Hassan Rouhani for their role in negotiating the 2015 nuclear deal, which they see as capitulation to Western powers.
During his presidential campaign, Trump called the nuclear agreement "the worst deal ever negotiated", raising questions over whether he would rip it up once he took office.
The historic deal between Iran and six major powers restricts Tehran's nuclear program in exchange for the lifting of international oil and financial sanctions against the Islamic Republic.
The Trump administration's inter-agency review of policy towards Iran will examine whether the lifting of sanctions against Tehran is in the US national security interests.
