The U.S. military is sending a three-star general to Puerto Rico along with several thousand more troops to help the recovery from Hurricane Maria amid mounting complaints that thousands of containers of supplies are stuck at San Juan's port because of red tape, lack of drivers and a crippling power outage.

Lt. Gen. Jeff Buchanan, commander of U.S. Army North, was set to arrive in Puerto Rico on Thursday evening.

John Cornelio, spokesman for U.S. Northern Command, said Buchanan is being sent to the island to better assess the situation so the military can provide the highest level of support for the disaster.

He cited problems getting supplies and aid to residents: 12 of the 29 bridges that have been assessed are closed; another 65 are damaged.

Cornelio also said the number of open gas stations has increased from about 400 to 676.

Although some fuel, water and medicine is trickling into the interior of the island, local and state officials said the response has been too little, too late.

In Washington, Homeland Security Adviser Tom Bossert pushed back Thursday on reports that the federal response has been slow, blaming "misreporting."

San Juan Mayor Carmen Yulin Cruz, speaking to CNN about the logjam at the port, said she asked the Federal Emergency Management Agency to allow municipalities to distribute goods themselves because "we can get the stuff where it needs to go." She said she was told to write a memo about that.

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“Now is not the time for memos, now is the time for action, now is the time for justice, now is the time to get life-supporting supplies into people’s hands,” the mayor said.

"Three thousand containers are stuck there, and there is no reason at all," she said. "My cry is, 'Let's get it done.'" As of Thursday, there were more than 10,000 containers at the site awaiting distribution, according to Puerto Rican state officials.

Amid the devastation from Maria, every problem seems to compound the next. Gov. Ricardo Rosselló said desperately needed truck drivers were themselves dislocated by the storm, and — amid widespread power and communications outages — they were difficult to track down.

He told MSNBC that Puerto Rico has received 4 million liters of water and expects to get another 7.5 million more.

"Our biggest challenge has been the logistical assets to try to get some of the food and some of the water to different areas of Puerto Rico," he said.

Puerto Rico got one important boost on Thursday when President Trump, after initially resisting, waived shipping restrictions for the island at Rosselló's request and after an outcry from Congress about shortages of fuel, food and emergency supplies.

Authorities reported slow progress: 44 out of 69 hospitals up and running, 50 municipalities getting supplies, and 5,500 people rescued. Rosselló told CNBC that he has used "runners" to report on the needs of various towns and cities and has deployed satellite phones to local mayors.

“This is the single biggest, major catastrophe in the history of Puerto Rico, bar none, and it is probably the biggest hurricane catastrophe in the United States,” Rosselló said Wednesday as he delivered aid to the southern town of Salinas, whose mayor says 100% of the agriculture there was wiped out when winds tore up plantains, corn, vegetables and other crops.

Rosselló said state National Guard troops are now engaged, and he said he asked the Defense Department to send special troops for transport, fuel and food deployment and engineering needs.

"The food is here and the water is here. Critically what we need is equipment, human resources, whether national guard or state guard," the governor said.

He told reporters Thursday that the governors of New York and New Jersey were sending their National Guard troops, and that governors of other states had pledged similar assistance.

Rosselló also noted that Puerto Rico's physical isolation as an island remains a major complicating factor.

"Puerto Rico, different to Florida or Texas, has no neighboring states that can actually drive to there and give quick aid," he said. "We need to fly assets over here and bring it by boat, and that has been a little bit of the bottleneck."

Sen. Marco Rubio. R-Fla., who visited the island this week, said conditions on Puerto Rico are "getting worse." He told CNN that the "logistical supply chain is broken" and that only a major presence by the U.S. military could help restore roads and get supplies distributed quickly throughout the island.

Bossert also said the U.S. Army Corp of Engineers was tackling the problem of the power outage across the island. The immediate goal was to restore temporary power, with diesel-run generators, then restore the permanent generators, then move to repairing transmission lines and hookups to houses.

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Bossert acknowledged problems trying to round up truck drivers scattered by the storm to help with the movement of goods from the port. But he said the immediate shortage had been augmented by the deployment of U.S. troops as drivers.

He blamed much of the perception of supply problems with out-of-date information and "misreporting."

There are 10,000 federal forces on the island, including different agencies, and 7,200 troops, including the Coast Guard, Bossert said.

Military helicopters were used to take patients from hospitals that were not functioning to those that were during the critical first days after the storm, he said.

He also said security forces were now in place to protect truck drivers delivering water and food during this time of chaos.

Alex De La Campa, who was designated by Trump as federal coordinating officer for relief efforts, acknowledged that truck drivers were unavailable the first couple of days after the storm but said the are now delivering commodities. No FEMA supplies are sitting in ports for lack of trucking, he said.

“All FEMA commodities are moving as we receive them,” De La Campa said. “There is not a single trailer from FEMA or response operations that are at the airport or the port.”

As with food and water, the problem is not a shortage of gasoline, but of distribution.

According to Tim Freccia, a journalist in Puerto Rico reporting for weather.com, about half of the U.S. territory's gas stations are inoperable.

"People are gonna get desperate," Alexis Colon, fuel officer for the U.S. Coast Guard, told weather.com. "They're already desperate, I can tell you."

"The fuel is on the island," Colon said. "It's just a question of getting it from the piers to the gas stations."

The problems have brought near paralysis to the economy and to the lives of many individuals.

Long lines have formed at banks or around the scattered ATMs that are operational. Without money, people can't pay for scarce goods even when they find them.

Many people are also unable to work or run their businesses because diesel to run generators is in short supply or they can’t spend all day waiting for gas to fill their car.

Engineer Octavio Cortes predicts it will only get worse because so many of the problems are inter-connected and cannot be easily resolved.

“I don’t know how much worse it’s going to get,” Cortes told the Associated Press as he joined other motorists stopping on a bridge over a river in northern Puerto Rico to catch a faint cellphone signal. “Right now it’s manageable, but I don’t know about next week or after that.”

Contributing: Bart Jansen, USA TODAY; Associated Press