SAN JUAN, Puerto Rico (Reuters) – Puerto Rico officials pressed the Trump administration on Wednesday to lift a ban on foreign shipping between American ports while the U.S. island territory struggled with fuel, water and medical shortages one week after Hurricane Maria struck.

Even as federal emergency management authorities and the U.S. military stepped up relief efforts, many residents on the island of 3.4 million people voiced exasperation at the prolonged lack of electricity, reliable drinking supplies and other essentials.

Maria, the most powerful hurricane to hit Puerto Rico in nearly 90 years, swept across the island with roof-ripping winds last Wednesday, knocking out the territory’s entire power grid, unleashing severe flooding and causing widespread heavy damage to homes and infrastructure.

The storm claimed more than 30 lives across the Caribbean, including at least 16 in Puerto Rico. Governor Ricardo Rossello called the devastation an unprecedented natural disaster.

Medical experts said they were concerned about a looming public health crisis posed by the island’s crippled water and sewage treatment system. The delivery of relief supplies has been complicated by communication outages and roads still damaged by flooding or left impassable by fallen trees, wires and debris.

Desperate residents have waited hours in long lines for deliveries of diesel fuel to power generators and gasoline to refill empty automobile tanks. Some water-supply trucks have been mobbed.

Rossello has strongly praised the response of U.S. President Donald Trump, defending the Republican administration against complaints of being slow to act and showing too little concern.

On Wednesday the governor and others pushed Trump to temporarily waive the Jones Act, a law requiring that all goods shipped between U.S. ports be carried by U.S. owned-and-operated vessels.

Administration officials on Tuesday balked at the idea, saying there was sufficient shipping capacity for emergency deliveries to Puerto Rico in the U.S. merchant fleet, but Trump said on Wednesday that a waiver was under consideration.

“We’re thinking about that,” Trump told reporters. “But we have a lot of shippers and …. a lot of people that work in the shipping industry that don’t want the Jones Act lifted, and we have a lot of ships out there right now.”

Puerto Rico typically gets most of its fuel by ship from the United States, but one of its two main ports is closed and the other is operating only during the daytime.

“We expect them to waive it (the Jones Act),” Rossello told CNN on Wednesday, noting there was a brief waiver issued after Hurricane Irma, which was much less devastating as it grazed past the island en route to Florida earlier this month.

Members of Congress from both parties have supported an emergency waiver, he said.

The U.S. government has issued periodic Jones Act waivers following severe storms in the past, including Irma and Hurricane Harvey, which ravaged the coastal Texas and Louisiana in August.

LACK OF WATER, FUEL

Growing frustration levels were evident among throngs of island residents struggling on a daily basis to cope without basic necessities.

Despite gasoline rationing, service stations have been able to stay open just a few hours at a time, and more than 91 percent of cellular communication sites remained out of service, U.S. officials said.

Electrical outages also have left many without internet or cable services, while at least nine radio stations and one television broadcaster were still off the air on Wednesday.

Most hospitals were without electricity or adequate fuel for generators, though the island was expected to get some medical relief next week with the arrival of the 1,000-bed U.S. Navy hospital ship Comfort, due to sail from its home port in Virginia on Friday. {nL2N1M900P]

Long-term power restoration will require a rebuilding of generation, transmission and distribution facilities, according to the Federal Emergency Management Agency (FEMA), which oversees the disaster response.

On Tuesday, hundreds of people crowded around a government water tanker in the northeastern municipality of Canovanas, some 15 miles (25 km) east of the capital San Juan, with containers of every size and shape after a wait that for many had lasted days.

“I know there can be more help,” said Juan Cruz as he filled a container. Residents there said it was the first such truck to visit their neighborhood since the hurricane struck.

“We can use more help,” Cruz said. “We are U.S. citizens. We are supposed to be treated equally.”

U.S. Air Force Colonel Michael Valle, on hand for relief efforts in San Juan, said he was most concerned about “the level of desperation” that could arise if fuel distribution did not return to normal within a couple of weeks.

San Juan resident Joselyn Velasquez said she thought aid was too slow to arrive.

“They say that it is coming from the United States, but who are they giving it to because I haven’t received any at my house?” Velasquez asked. “No one has knocked on my door and said, ‘Here is some rice.’”

The FEMA said that by Wednesday that it had delivered more than 4.4 million meals and 6.5 million liters of water in Puerto Rico and the U.S. Virgin Islands since Maria ravaged the Caribbean.

In Washington, Republican leaders who control both chambers of Congress have said they are prepared to boost disaster funding, but are waiting for a detailed request from the Trump administration.

In the meantime, the administration still has $5 billion in aid in a disaster relief fund, and Congress has also approved about $7 billion more that will become available on Oct. 1.