In this Oct. 26, 2010 file photo, a worker rides a bike in front of the reactor building of the Bushehr nuclear power plant, just outside the southern city of Bushehr, Iran. (AF photo)

TEHRAN, May 7 (Xinhua) -- Iran's Foreign Ministry spokesman said Monday that withdrawal from Iranian international nuclear deal is not as easy as it may seem.

Bahram Qasemi said the 2015 deal has its own complexities and U.S. withdrawal would not be easily feasible.

However, if the United States decides to do so, Iran's reaction would be "painful" for Washington and will make them regret it, he said at his weekly press conference.

Besides, the United States should accept the consequence of their decision, he said.

Qasemi reiterated that Iran will not be the first to exit the deal, but it is prepared for any scenario.

U.S. President Donald Trump is expected to decide by May 12 whether to pull out of the nuclear deal, and he has said that he would not extend the waiver suspending the U.S. sanctions on Iran.

In January, Trump extended sanctions relief on Iran under the deal for the last time, threatening to withdraw from it if U.S. congress and his European allies cannot fix the alleged "disastrous flaws."