“We are in close contact with London and other partners around the world.
They are also watching this, ”TASS quotes her.
Psaki noted that "the first reports are deeply troubling."
Earlier, the UK Maritime Trade Organization announced the incident with the vessel in the Gulf of Oman, describing it as a "potential hijacking".
According to Sky News, citing sources, a group of "eight or nine armed men" boarded the Asphalt Princess tanker.