Iranian President Hassan Rouhani has warned that Washington "will regret it" if the United States violates a 2015 deal between Tehran and global powers to curb Iran's nuclear program.

"We will not be the first to violate the accord but they should definitely know that they will regret it if they violate it," Rouhani said at a conference in Tehran on April 9, which is National Nuclear Technology Day in Iran.

"We are much more prepared than they think, and they will see that if they violate this accord, within a week, less than a week, they will see the result," Rouhani said.

U.S. President Donald Trump has threatened to pull the United States out of the deal and reimpose sanctions on Iran by May 12 unless new limits are placed on Tehran's nuclear and missile programs.

Rouhani remarked: "It's been 15 months since this gentleman who came to power in America has been making claims and there have been many ups and downs in his remarks and his behavior."

He added that the "foundations" of the deal "have been so strong that during these 15 months of pressure...the structure has remained solid."

AFP,Reuters