Iran has arrested a dual national who also holds US citizenship for "acting against national security", the ISNA news agency said on Wednesday.

The man was arrested in mid-July in the northern town of Gorgan near the border with Turkmenistan, ISNA quoted the intelligence services of the elite Revolutionary Guard as saying, without giving his name.

The dual national is "accused of links with enemy governments, acting against national security and links with counter-revolutionary elements and media".

"He was handed over to justice," ISNA said, without providing any further details.

Tehran, which signed a landmark nuclear deal with world powers including Washington last year, does not recognise dual nationality and treats those arrested as Iranian citizens only.