The White House has announced a full review of the 2015 decision to lift sanctions against Iran.
USA secretary of state says Tehran's behaviour undermines U.S. interests in Syria, Iraq, Yemen and Lebanon.
Votel said that, since the agreement was finalized, the US military has seen a heightened number of "malign activities" on the part of Iran and its proxies in the Central Region, including "Iraq, Syria, Afghanistan, Pakistan, Yemen, Egypt, the Sinai, and the Bab-el-Mandeb Strait [located between Yemen and Djibouti and Eritrea] and in other parts of our area of responsibility".
In a statement that was published, Tillerson stated that Iran continues to stand behind its commitments made in the nuclear deal that was signed in 2015 but the USA government is still concerned about how Iran "remains a leading state sponsor of terror".
Tillerson told reporters the review, which he announced on Tuesday, would not only look at Tehran's compliance with a 2015 nuclear deal but also its behaviour in the region which he said undermined USA interests in Syria, Iraq, Yemen and Lebanon. Last month Secretary of Defense James Mattis called Iran the "world's biggest sponsor of state terrorism".
"It remains a leading state sponsor of terror, through many platforms and methods", Tillerson said.
Though there was no sign the Trump administration meant 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.
At the time, officials stressed that a violation of the UN Security Council resolution on Iranian ballistic missile activity would not impact the Iran nuclear deal. Iran has defended its nuclear programme as purely civilian. Tuesday's was the first update for the Trump administration.
The U.S., Iran and other major powers signed the JCPOA, commonly known as the Iran nuclear deal, in 2016. He said those attempting to undermine or destroy the JCPA will not succeed, adding that those countries involved in the agreement should follow through - perhaps a statement directed at the United States and Trump, who said the deal is one of the worst in history.
The European Union's foreign policy chief, Frederica Mogherini, said last month after meetings with senior Trump administration officials she was reassured in the talks that the USA was committed to fully implementing the deal.