Iran's President Hassan Rouhani says the international sanctions regime has crumbled and will not be rebuilt even if Iran and world powers fail to reach a final nuclear deal by a July 20 deadline.

Rouhani told a press conference Saturday that it is still possible to reach a comprehensive accord before the deadline and that his government will in any case remain committed to its policy of constructive interaction.

"If we can't reach a final agreement in negotiations by July 20... Conditions will never go back to the past. The sanctions regime has been broken," Rouhani said.

Iran and the five permanent members of the U.N. Security Council plus Germany reached an interim deal in November that limited Iran's uranium enrichment program in exchange for the easing of some sanctions.