The US Army is increasing its operations in Puerto Rico to help with the island's reconstruction after the devastation caused by Hurricane Maria, which destroyed infrastructure of all sorts, killed 16 people and has caused serious distribution problems for fuel and supplies.

On Thursday, President Donald Trump placed Lt. Gen. Jeffrey Buchanan in charge of military operations to aid Puerto Rico in recovering from the storm, according to the US Northern Command.

The Northern Command said in a statement that Buchanan was expected to arrive in Puerto Rico later on Thursday to direct operations there.

Buchanan is the officer who headed military operations in New Orleans after the devastation caused by Hurricane Katrina in 2005.

The president of the United States on Thursday also authorized foreign ships to deliver much-needed supplies to hurricane-ravaged Puerto Rico, the White House press secretary said.

Currently, the Northern Command is carrying out search and rescue and supply operations on the island, and the Army is also working to reestablish electric power at hospitals, ports, airports and for other critical infrastructure.

With the naming of a general with experience in natural disasters, it appears the White House is taking to heart the recent criticism by storm victims and lawmakers, who have accused Trump of not attaching sufficient importance to the island's situation.

Until Buchanan's appointment, Brig. Gen. Richard Kim had been the officer responsible for coordinating the military assets in cooperation with personnel from federal agencies who have arrived on the island from the US mainland. In concert with local authorities, the Army and other federal agencies are focusing their efforts on Thursday on getting fuel and assorted basic supplies flowing where they need to go.

The objective has been to break the "bottleneck" or "plug" that has developed in the distribution chain - caused mainly by the lack of truckers - and enable the public to get access to fuel at service stations, one of the main problems that has arisen along with the collapse of the electric grid and infrastructure.

Gasoline is a basic need for the general public but also for local hospitals to supply their diesel generators to keep the lights and air conditioning working given the lack of electricity. Supermarkets, too, need the fuel for their generators so that they can keep fresh food and ice available to the public, with many people complaining over the lack of help in the wake of the storm.

Some 9,500 containers with all sorts of supplies have been "logjammed" at the island's ports because there are not enough truckers to distribute them, given that they themselves are incommunicado, need to attend to their own families' problems or are concerned about the lack of security among an increasingly desperate population.

Eight days after Maria lashed the island, the public is still dealing with the lack of gasoline and food, a situation that arouses great anxiety for many local residents.

The head of the Federal Emergency Management Agency (FEMA) in Puerto Rico and the Caribbean, Alejandro de la Campa, said at a Thursday press conference that military contingency plans that had never before been activated have been set into motion in Puerto Rico in this instance and that four generals are coordinating the Army's operations.

Puerto Rico Gov. Ricardo Rossello said that there are 1,460 members of the National Guard in Puerto Rico and that authorities have requested that certain US states sent more troops, noting that two Category 5 hurricanes have hit Puerto Rico in recent weeks but asserting that action is being taken and results are being seen.

 He also called upon the Puerto Rican public for "patience and prudence," noting that Hurricane Maria has been an "unprecedented" disaster for the US territory.

Rossello also said that on Thursday the island's main hospital, the Medical Center, will once again have electricity and the aim is to get the power back on at the San Juan Convention Center, the headquarters for post-hurricane operations.