Rouhani added, "Our response will be stronger than what they imagine and they would see that within a week".
The U.S. president has called on European powers to "fix" what he says are the "terrible flaws" of the deal by that date.
Iran agreed to measures that bar its way to the development of a nuclear weapon in return for the signing of the nuclear deal and its removal of the most damaging economic sanctions, against areas such as oil exports and central bank activities.
In early March, Iranian Foreign Minister Mohammad Javad Zarif forewarned on state television: "If the United States makes the mistake of pulling out of the JCPOA, it will definitely be a painful mistake for the Americans".
US President Donald Trump has threatened to walk away from the nuclear deal and reimpose sanctions by May 12 unless tough new restrictions are imposed on Iran's nuclear and missile programmes.
The EU said in a statement it had taken note of Trump's decision and would assess its implications.
"Our relations with our neighbors will be friendly relations", Rohani said.
He said it was not yet clear who had carried out the attack.
The official IRAN daily said Col. Mehdi Dehghan, a member of the Guard's aerospace force, was killed in the attack.
Iran is a key ally of Syrian President Bashar Assad and has sent troops to bolster his forces.
"If any country's airplanes dare to near Iran's airspace, the air defense will definitely give a crushing response", Esmaili said.
Trump laid out several conditions to keep the U.
Head of the Atomic Energy Organization of Iran, Ali Akbar Salehi, said that domestic experts have managed to renovate Tehran Research Reactor (TRR), a 5 megawatt-thermal pool-type light water research reactor.
"However, we continue to closely watch the situation and support the ongoing diplomatic efforts to hold those who use chemical weapons, in Syria and otherwise, accountable".
Pedestrians walk past a currency exchange shop with current rates for the USA dollar and the euro not displayed, in downtown Tehran, Iran, Tuesday, April 10, 2018. Israel also destroyed the drone's remote guidance system and two additional Iranian targets in Syria. Work already has begun on this front, the official said.