Sen. John McCain urged the Department of Homeland Security on Tuesday to waive a law that would allow foreign ships to send supplies to Puerto Rico after the U.S. territory was ravaged by Hurricane Maria last week.

Conditions in Puerto Rico remain dire, and 3.4 million people are virtually without electrical power, while food and drinking water remain scarce.

But the Merchant Marine Act of 1920, also known as the Jones Act, requires shipments between U.S. ports be carried out exclusively by vessels built and operated by Americans.

That prevents Puerto Rico from receiving shipments from the continental U.S. aboard foreign ships, even though it may be cheaper and faster.

The Trump administration ruled out temporarily setting aside the Jones Act, even though the government had waived those rules in Florida and Texas until last week.

After the DHS denied the request of eight U.S. representatives to waive the Jones Act on Monday, McCain stepped in urging the department to reconsider.

“I am very concerned by the Department’s decision not to waive the Jones Act for current relief efforts in Puerto Rico, which is facing a worsening humanitarian crisis following Hurricane Maria,” McCain wrote.

“I am very concerned by the Department’s decision not to waive the Jones Act for current relief efforts in Puerto Rico, which is facing a worsening humanitarian crisis following Hurricane Maria,” McCain wrote.

“It is unacceptable to force the people of Puerto Rico to pay at least twice as much for food, clean drinking water, supplies and infrastructure due to Jones Act requirements to as they work to recover from this disaster,” McCain wrote.

The senator, who has long pushed for repealing the Jones Act, called for the law to be scrapped, claiming it “would lead to hastened recovery efforts where our country needs it most.”

Gregory Moore, a spokesperson for DHS, said the problem was not the number of U.S. vessels moving commodities to Puerto Rico, but the capacity of their ports to offload and transit supplies.

After Trump was criticized for tweeting about professional athletes protesting the national anthem this weekend, he ramped up his response to Puerto Rico, announcing he would visit the U.S. territory next week.

Conditions in Puerto Rico remain dire, and 3.4 million people are virtually without electrical power, while food and drinking water remain scarce. (HECTOR RETAMAL/AFP/Getty Images)

Brock Long, administrator of the Federal Emergency Management Agency, said Tuesday that 16 Navy and Coast Guard ships were in the waters around Puerto Rico, with 10 more on the way.

Puerto Rico has long railed against the Jones Act, saying it makes the cost of imported basic commodities, such as food, clothing and fuel, more expensive.

“Our dependence on fossil fuel imports by sea is hampering the restoration of services,” said Juan Declet-Barreto, an energy expert at the nonprofit group the Union of Concerned Scientists.

The refusal to allow the waiver “is raising fears on the island that they are going to be left behind in this disaster.”

With News Wire Services