President Trump said Friday that the federal government is committed to helping rebuild infrastructure on Puerto Rico after Hurricane Maria, but that "we've never seen a situation like this."

Trump said 10,000 federal personnel are assisting with the recovery efforts and that "we are literally starting from scratch."

"The response and recovery effort probably has never been seen for something like this," he said. "This is an island, surrounded by water — big water, ocean water."

Democrats, including Hillary Clinton, criticized the amount of time Trump spent discussing Puerto Rico's situation, opening a potential political vulnerability.

On Thursday Trump waived the Jones Act, which forbids foreign-flagged ships from doing commerce between U.S. ports, to help with the island's recovery, after initially saying he might not because of U.S. shipping industry interests.

Trump set expectations low for the speed of recovery, saying the storm's Sept. 20 landfall in Puerto Rico and a strike by Hurricane Irma on the U.S. Virgin Islands two weeks earlier were so devastating that "there is nothing left." He said even truck drivers had to be imported.

"The houses are largely flattened, the roads are washed away, there is no electricity, the plants are gone," Trump said of the islands. "The plants are gone, it's not like let's send in a crew to fix them, you have to build brand new electric. The sewage systems have been wiped out."

In addition to discussing the logistics of recovery, Trump alluded to future considerations about who would pay for the work.

"Ultimately the government of Puerto Rico will have to work with us to determine how this massive rebuilding effort — it'll end up being one of the biggest ever — will be funded and organized, and what we will do with the tremendous amount of existing debt already on the island," he said.