We are convinced of the peaceful nature of our nuclear energy program, so we have no principled objections to further inspections and more, he says on state TV.
He also adds that "if Iran wanted to invest in nuclear weapons, it would have already done so".
The statement comes ahead of expected talks between the US and Iran on Friday in Rome. It will be the fifth round since the talks began in April. Oman is acting as a mediator in the talks.
Araghchi says that there are still "fundamental differences" between the two sides in the talks. He warns that there will be no agreement at all if the US wants to prevent Iran from enriching uranium.