ERBIL, Kurdistan Region of Iraq - US President Donald Trump on Friday claimed that Iran targeted ships transiting the Strait of Hormuz using one-way attack drones, calling it a "foolish violation" of the ceasefire agreement with Washington.

"Iran shot at least four One Way Attack Drones at Ships in the Strait of Hormuz. One solidly hit the upper deck of a large, expensive Cargo Ship. Damage was done, but the Ship proceeded on its way," Trump wrote on Truth Social.

"We knocked down the other three. Obviously, this is a foolish violation of our Ceasefire Agreement," he concluded.

Tensions have remained high in the strategic waterway since the inking of a bilateral memorandum of understanding (MoU) between Washington and Tehran on June 17, with Iranian state media reporting on Friday that a communications channel has been opened between both sides to prevent incidents in the threat from escalating into military confrontations.

Describing what he termed as a deconfliction channel, US Vice President JD Vance, in an interview with the British news site UnHerd published on Thursday, said members of US Central Command (CENTCOM) and Iran's Islamic Revolutionary Guard Corps (IRGC) have been sent by their respective sides to "go hang out in Doha" and consult one another on any potentially escalatory situation.

The Wall Street Journal, citing unnamed US officials, reported that a Singapore-flagged tanker was attacked by the IRGC as it transited the Strait on Thursday, with a one-way attack drone allegedly having been used in the strike.

The UK Maritime Trade Operations center reported that the vessel's bridge was damaged but no casualties were incurred.

The IRGC Navy on the same day had criticized proposed safe-passage routes for transiting vessels announced by Oman and the International Maritime Organization (IMO), insisting that "safe passage through the Strait of Hormuz is only possible through the routes announced by Iran."

Both Oman and Iran have been negotiating the future conditions through which commercial vessels may pass through the waterway, which was closed by Tehran during the US-Israeli military campaign against Iran that commenced in late February, wreaking havoc on international shipping.

Despite US objections, Iran has asserted that it will impose a mechanism whereby vessels must pay fees for passage once the 60-day grace period provided for in the MoU expires.

Oman has offered mixed signals regarding any prospective tolling mechanism, with the foreign ministry having stressed that transit will be "toll-free" in recent days while Bloomberg on Friday reported that Muscat has informed allies that management of the Strait will not return to its pre-war precedent and that payments may be required for passage.