Trump praised the federal disaster response team that's working to help the island recover, including his FEMA administrator and acting Homeland Security Secretary Elaine Duke, who found herself accused of insensitivity after she called Puerto Rico a "good news story" on Thursday.
WATCH: San Juan Mayor Carmen Yulin Cruz expressed her frustrations on Friday of the response to relief efforts in Puerto Rico following Hurricane Maria.
Mr Trump said "they want everything to be done for them when it should be a community effort".
Trump touted the federal government's response on the island, saying the workers there are doing "a fantastic job".
Trump, who says he will visit the island Tuesday, has been slow to react to pleas, but quick to respond to criticism that he has given Puerto Rico less attention than he gave to Texas and Louisiana after Hurricane Harvey and Florida, where he keeps a second weekend home, after Irma.
He also tweeted: "Results of recovery efforts will speak much louder than complaints by San Juan Mayor".
While FEMA has said it has delivered millions of meals and liters of water, many Puerto Ricans have said the aid has been too little and has not made it way to large parts of the island.
"I don't know what world Trump is living in", he said. Carmen Yulin Cruz spends her days in hip waders trudging through filthy flood waters, going door to door to rescue people in need, and begging, sometimes through tears, for the White House to do more to save her people, all while Trump plays golf.
A man stands inside of a destroyed supermarket by Hurricane Maria in Salinas, Puerto Rico, on September 29, 2017.
"Most of our nursing homes have people that have an inability to move, so they're stuck in the 14th floor, they have no water, they have no food, they - majority are insulin-dependent", she said. "The governor called and said, 'Look, you do.' And they did it right away", she said.
In remarks to the National Association of Manufacturers in Washington, Trump also defended his administration's response to the crisis in Puerto Rico.
President Trump called such reports "fake news" throughout the day on Saturday. "We know our people in Puerto Rico will continue to work hard until the island is up and running".
Officials and residents of the US island devastated by Hurricane Maria say that's not true. "We look forward to being able to help in any capacity we can in Puerto Rico".
After Trump's tweets, Cruz said on MSNBC she wasn't "saying anything nasty" about him.
Across the island, people were continuing to wait for concrete signs of federal and local collaboration - for food, for potable water, for gas, for anything.
Mr. Trump's weekend tweets have shown him to be contemptuous of any complaints of a laggard United States response to the natural disaster that has imperiled the island's future. Criticism of federal relief efforts continues to intensify as numerous supplies that have been delivered to the island remain out of the hands of the communities that need them.
The creator of Broadway hit "Hamilton", Lin-Manuel Miranda, whose parents moved to NY from Puerto Rico, took Trump to task on Twitter over his attack on Cruz: "She has been working 24/7".
Mulvaney said some people were looking for reasons to snipe at the Trump administration and that the public should consider the administration's actions over words.