The US has bowed to pressure to let an overseas-flag MR tanker into hurricane-hit Puerto Rico with much-needed diesel cargo.

Homeland security secretary Alejandro Mayorkas announced a “temporary and targeted” waiver of Jones Act restrictions for Hayfin Capital’s 50,000-dwt GH Parks (built 2009), which had been idling off the coast with 300,000 barrels of fuel on board.

Hundreds of thousands of people on the island remain without power following flooding caused by Hurricane Fiona, but US labour unions had opposed any relaxation of foreign flag rules for shipping.

Mayorkas said the waiver had been granted as a "response to urgent and immediate needs of the Puerto Rican people."

The tanker will dock to give the population sufficient diesel to run generators needed for electricity and the functioning of critical facilities as they recover, the politician added.

“The decision to approve the waiver was made in consultation with the departments of transportation, energy, and defence to assess the justification for the waiver request and based on input from the governor of Puerto Rico and others on the ground supporting recovery efforts,” Mayorkas said.

His statement went on to reiterate that the Jones Act is vital to maintaining the strength of the American shipbuilding and maritime industries by requiring all maritime cargo transport between US ports to occur on US-flag vessels.

When these ships are not available to meet national defence requirements, the department of homeland security may grant waivers.

AIS data showed the Marshall Islands-flag GH Parks underway in the Caribbean 10 hours ago.

Keli’i Akina, president of Hawaii’s Grassroot Institute, welcomed the move but said Mayorkas’ order should be broadened and extended.

Permanent waiver?

“We are glad to hear that the Biden administration will allow critical fuel supplies on the GH Parks to reach the residents of Puerto Rico,” Akina said.

He wants the waiver to apply to all ships and extended for at least a full year to be sufficiently effective.

Akina said the limited waiver “recognises that the Jones Act imposes significant economic costs on the island’s residents, especially during times of crisis, such as now with Hurricane Fiona and back in 2017 when the territory was slammed by Hurricane Maria.”

He added that, ideally, the exemption should be permanent, to eliminate potentially harmful delays in future relief efforts — as well as to just help improve the quality of life for Puerto Ricans under normal circumstances.

The GH Parks is operated by Hayfin’s Greenheart Management in the UK and has been chartered by Puerto Rico distributor Peerless Oil & Chemical.

The Puerto Rican government told CBS News that it believed BP was connected to the diesel shipment. BP has not commented.

The UK oil major chartered the vessel for six months plus options last year.

Homeland Security Secretary Alejandro Mayorkas has granted a temporary waiver to a Hayfin Capital tanker. Photo: US government