UPDATE 2-Under fire, Trump blames Puerto Ricans for slow hurricane response

(Adds response from San Juan mayor, New York City Council speaker, San Juan resident)

SAN JUAN, Puerto Rico, Sept 30 - U.S. President Donald Trump blamed Puerto Ricans on Saturday for the slow pace of relief from the devastating damage caused by Hurricane Maria, saying his government, which has come under fire for its response, was doing an "amazing job."

Trump took to Twitter early on Saturday to fire back at the mayor of San Juan, the island's largest city. On Friday, Carmen Yulin Cruz had criticized Trump's Republican administration and begged for more help, pleas that received widespread television coverage in the mainland United States.

Maria, the most powerful storm to strike Puerto Rico in nearly 90 years, wiped out the power and communications systems, making it difficult to get food, water and fuel around the island. The hurricane has killed at least 16 people, according to the official death toll.

Trump, who was spending the weekend at his private golf club in Bedminster, New Jersey, said Cruz was attacking him for partisan reasons.

"Such poor leadership by the Mayor of San Juan and others in Puerto Rico who are not able to get their workers to help," said Trump, who is slated to visit the island on Tuesday. "They want everything to be done for them when it should be a community effort."

Cruz, who has been living in a shelter after her home was destroyed in the hurricane, told MSNBC that the issue was not personal and said municipal employees were working as hard as they could.

"Actually, I was asking for help - I wasn't saying anything nasty about the president," Cruz said. "I am not going to be distracted by small comments, by politics, by petty issues.

Trump's comments drew swift condemnation on the mainland.

"The tweets this morning are despicable, are deplorable, are not statesman-like at all," said New York City Council Speaker Melissa Mark-Viverito, a Democrat who was born in Puerto Rico.

"He needs to be in charge, he needs to take control, he needs to demonstrate some level of empathy over what is happening," Mark-Viverito said on CNN.

Trump was scheduled to speak by telephone to the governor of Puerto Rico, Ricardo Rossello, and other officials from the region on Saturday, and U.S. Vice President Mike Pence visited the Federal Emergency Management Agency's headquarters in Washington for a briefing.

At a news conference, Rossello declined to comment on Trump's tweets, which he said he had not seen.

"Let me stress this: I am committed to collaborating with everybody," he said. "This is a point where we cant look at small differences and establish differences based on politics."

The Trump administration has given Puerto Rico's government "whatever we ask for" in the immediate aftermath of the hurricane, Rossello said. But he warned that the U.S. Congress would need to help rebuild the island, which is home to 3.4 million Americans.

"If Congress doesnt take action with a significant package, then we are looking at a possible humanitarian crisis," he said. What are the effects of falling into that predicament? Massive exodus without a doubt."

The insurance industry has begun to tally the mounting costs of Maria, with one modeling company estimating that claims could total as much as $85 billion. Puerto Rico has incurred most of the damage.

San Juan resident Judith Berkan said power shortages and long lines for cash, food, gasoline, and medical clinics were wearing people down.

"Things don't seem to be getting better," Berkan, a lawyer, said in a text message.

"Although there are great moments of solidarity on the ground here, you can also see that patience is growing thin."

(Reporting by Gabriel Stargardter, Robin Respaut and Nicholas Brown in SAN JUAN, James Oliphant in BRANCHBURG, N.J., Lesley Wroughton and Roberta Rampton in WASHINGTON, Suzanne Barlyn in NEW YORK and Alex Dobuzinskis in LOS ANGELES; Writing by Roberta Rampton; Editing by Chizu Nomiyama and Lisa Von Ahn)