When US President Donald Trump visited Puerto Rico last week and saw first-hand the destructive aftermath of Hurricane Maria, he reaffirmed the US' commitment to rebuilding the reeling island.

On Thursday, however, he adopted an altogether different tone and indicated that the federal government would not be sticking around for the long haul.

Read more: US President Donald Trump in Puerto Rico says Hurricane Maria devastation not 'real catastrophe'

In a series of tweets, the presidents insisted that Washington could not keep sending help "forever" and that "electric and all infrastructure was disaster before hurricanes."

Trump's remarks prompted, not for the first time, a war of words with Yulin Cruz, the mayor of Puerto Rico's capital San Juan.

Cruz tweeted that the president's remarks were "unbecoming" for a commander-in-chief, and "seem[ed] more to come from a 'Hater in Chief."

Later on Thursday, in letter to a member of Congress, Cruz accused Trump of being "incapable of empathy" and that his remarks "seem to be taken out of a book on 'how to add insult to injury' rather than a book on 'how to help during a humanitarian crisis.'"

Trump's tweets also drew rebuke from among Democratic lawmakers. Three weeks on from Hurricane Maria, which killed 45 people on the island, 85 percent of Puerto Rico residents still lack electricity and one third are without clean running water.

Although Puerto Rico is not a US state, its residents are US citizens. "It is shameful that President Trump is threatening to abandon these Americans when they most need the federal government's help," said Maryland Representative Steny Hoyer, the second-ranking House Democrat.

US House of Representatives sweepingly approves aid package

As Trump and Cruz's war of words played out, the US House of Representatives overwhelmingly approved a $36.5-billion (€30.9 billion)disaster aid package, which also includes assistance for Puerto Rico's cash-strapped government.

House Speaker Paul Ryan of Wisconsin said the government needed to ensure that Puerto Rico could "begin to stand on its own two feet" and that the US had "to do more to help Puerto Rico rebuild its own economy."

The package for Puerto Rico comes on top of the $15 billion in aid approved to Texas and Florida following Hurricane Irma, while tens of billions are expected to be requested and appropriated.

That has some Republicans wary of how Washington allocates its budget for future disasters. In Thursday's Wall Street Journal, Mark Walker, who chairs the House's conservative Republican Study Committee, wrote that disaster spending must be balanced with cuts in federal spending elsewhere.  "Governing by crisis is irresponsible, especially considering the national debt is already at $20 trillion," Walker said.

The cost of damage to Puerto Rico is estimated to be around $95 billion, or 150 percent of the island's gross domestic product. The US territory has faced years of economic challenges and was in the process of restructuring its $74 billion debt before Maria hit.

dm/bk (Reuters, AP, AFP)