Iranian President Hassan Rouhani said on Monday, May 22 Tehran would continue its ballistic missile program, state television reported, striking a defiant note after strong criticism of the Islamic Republic from U.S. President Donald Trump, Reuters reports.

"The Iranian nation has decided to be powerful. Our missiles are for peace and for defense ... American officials should know that whenever we need to technically test a missile, we will do so and will not wait for their permission," Rouhani said in a news conference, broadcast live on state TV.

Rouhani also criticized Iran's arch-foe Saudi Arabia over its lack of democracy, urging Riyadh to allow its people to decide their country's fate through free elections.

During a visit to Saudi Arabia, Trump stood in front of a gathering of leaders from across the Muslim world and called on them to isolate Iran which he said had “fueled the fires of sectarian conflict and terror.”