San Juan Mayor Carmen Yulin Cruz, with whom Trump has had a running war of words, tweeted that the president's comments were "unbecoming" to a commander in chief and "seem more to come from a 'Hater in Chief'".
Meanwhile, Texas and Florida - two states Trump won during last year's presidential election - also were struck by severe hurricanes recently, but the President has made no public indication that the federal government is pulling back on its response there.
FEMA says there are now some 19,000 federal civilian personnel and military service members - including more than 1,400 FEMA personnel - working in Puerto Rico and the U.S. Virgin Islands.
"In a trio of tweets, Trump wrote" "We can not keep FEMA, the Military & the First Responders, who have been unbelievable (under the most hard circumstances) in P.R. forever!" He said there was no current plan to withdraw troops who are supporting FEMA's recovery efforts. The spokesman said the agency aims to foster recoveries that are as swift as possible and that the length of their support varies based on the circumstances of each natural disaster.
White House legislative affairs director Marc Short said on CNN's "The Situation Room" that he did not view Trump's tweets as a "threat" to withdraw aid to Puerto Rico and conceded he did not know why Trump decided to make those statements Thursday morning.
"At the moment there's a humanitarian crisis that has to be attended to and this is an area where the federal government has a responsibility and we're acting on it", Mr. Ryan told reporters Thursday.
Congress is reportedly prepared to sign off on $6 billion in aid following hurricanes, including Maria in Puerto Rico..
A third of Puerto Ricans are without water, and 89 percent of residents there do no have electricity.
Maria devastated the island amid a severe financial crisis, with the government filing for bankruptcy in May.
Still, a separate Republican source who has been in touch with the administration on relief efforts in Puerto Rico questioned whether the President has a firm grasp on what his own administration is doing on the island.
During CNN's "New Day", Perry tangled with host Chris Cuomo, who has said the USA government is not doing enough to help Puerto Rico. Electric and all infrastructure was disaster before hurricanes.
In one out of a series of tweets, Warren said, "It is outrageous that @realDonaldTrump is making veiled threats to withdraw relief workers from U.S. citizens in need". "We're all Americans and we owe them what they need". But it is Trump's tone toward Puerto Rico that has drawn the most criticism. In an afternoon interview with MSNBC, Padilla said, "He is showing off that he is just racist". "It is not that you do not get it, it is that you are incapable of empathy and frankly simply can not get the job done".
The House bill includes a one-time payment of $1.27 billion to help Puerto Rico receive access to the U.S. Disaster Nutrition Program. Some $16 billion would go toward the National Flood Insurance Program to help it cover claims after reaching its borrowing limit.
More than a dozen years after Hurricane Katrina pounded the Gulf Coast, FEMA was slated to dole out almost half a billion dollars in fiscal year 2017 to fund relief efforts, mostly in Louisiana, after the hurricane and subsequent storms Rita and Wilma. Even long after a site is granted Superfund status, designating it a priority for the federal government, cleanup can take decades-and even then efforts are rarely able to eliminate all toxins. On Tuesday, the fund contained $6.72 billion.
Rubio said it is up to the oversight board charged with resolving Puerto Rico's debt crisis to determine how to address the island's debt, noting that private debt owed to investors with legal recourse can not simply be "forgiven" by the federal government. "'It's not a decision as is, it's a law that all the resources must be available for Puerto Rico".