TEHRAN, April 21 (Xinhua) -- Iran's atomic chief said here Saturday that Tehran would give a surprising response if the United States decides to scrap the 2015 international nuclear deal.

"We have said for several times that we hope that it would not happen, but we are prepared in a way to surprise the other side," Ali Akbar Salehi said, according to Tehran Times daily.

Iran is ready for any scenario from a technical point of view, the chief oh Atomic Energy Organization of Iran was quoted as saying.

Iran can resume enriching uranium to purity of 20 percent in four days if Washington decides to quit the deal, he warned.

Iran's foreign minister said on Friday that Tehran had a variety of countermeasures if Washington decides to pull out of the 2015 landmark nuclear deal.

"Iran has a wide range of options both inside and outside the JCPOA (the nuclear deal), and surely the reaction from Iran and the international community will be unpleasant for the Americans," Mohammad Javad Zarif told reporters upon arrival in New York City.

The JCPOA, short for the Joint Comprehensive Plan of Action, is an international agreement reached on July 14, 2015 between Iran and six world powers, namely China, France, Russia, Britain, the United States and Germany, plus the European Union.

U.S. President Donald Trump has repeatedly lashed out at the nuclear pact, in which the West promised to relieve sanctions on Tehran in exchange for a halt in Iran's efforts to develop a nuclear weapon.

Trump demands the elimination of sunset clauses for some of the restrictions the United States places on Iran from the nuclear deal. He also called for stronger inspection rules and limitation to Iran's development of long-range missiles.

But Iran says it will neither tolerate anything beyond its commitment to the nuclear deal, nor accept changes to the agreement.

Iran has threatened to withdraw from the deal if it cannot receive economic benefits.