President Trump said Friday he would "always be with" the residents of Puerto Rico, a day after he was criticized for tweeting that federal first responders who are helping the island recover from two hurricanes would not be there "forever."

"The wonderful people of Puerto Rico, with their unmatched spirit, know how bad things were before the H's. I will always be with them!" Trump tweeted Friday morning.

Democrats and Puerto Rico's leaders criticized Trump on Thursday for saying the federal response to the storms must end at some point.

Trump had been defending the federal response to Hurricanes Maria and Irma for weeks, amid Democratic complaints that not enough was done to help people immediately after the storm. Trump has said several times that Puerto Rico's shoddy infrastructure and $72 billion in debt set up the island territory for a tougher recovery.

Puerto Rico has been recovering from the Category 4 hurricane since it made landfall Sept. 20. Only 15 percent of people had power back this week, and communications around the island are not expected to be fully restored until later this year.

The Federal Emergency Management Agency said the "full force of the federal government" is working to help the U.S. Virgin Islands and Puerto Rico.

"While very real challenges to restoring damaged infrastructure remain, more than 19,000 federal civilian personnel and military service members are supporting the islands, working 24 hours a day in support of the hurricane disaster relief mission," FEMA said in a statement Thursday. "These efforts include restoring power and potable water, returning hospitals to operation, increasing fuel supplies, increasing cell phone coverage, and re-opening transportation facilities."

Trump also attacked Democrats on Friday morning for moving "so far LEFT" as they advocate for sanctuary cities that protect illegal immigrants.

"Hard to believe that the Democrats, who have gone so far LEFT that they are no longer recognizable, are fighting so far for Sanctuary crime," Trump tweeted.

On Thursday, the Justice Department announced it would give five U.S. jurisdictions one "last chance" to prove they will comply with federal immigration laws over the next two weeks.