An Iranian shipping company and an executive have been hit with US sanctions after another round of blacklistings amid rising tensions in the region.

Hafez Darya Arya Shipping, first sanctioned in 2018, has been hit with further sanctions while "principle executive" Majid Sajdeh was added to the list for shipping graphite to and from Iran.

The moves come alongside 17 other sanctions levied against companies operating in Iran's steel industry.