Adding to a series of unpresidential responses to Hurricane Maria, which devastated Puerto Rico in late September, President Donald Trump threatened to pull federal relief workers from the U.S. island on Thursday.

In response to the threat, San Juan Mayor Carmen Yulín Cruz—who has been forced to engage in public back-and-forths with the president in light of the natural disaster—referred to his actions as that of a “Hater-in-Chief.”

“Your comments about Puerto Rico are unbecoming of a Commander in Chief they seem more to come from a ‘Hater in Chief,’” Cruz tweeted.

“We cannot keep FEMA, the Military & the First Responders, who have been amazing (under the most difficult circumstances) in P.R. forever!” Trump tweeted early Thursday morning.

Trump’s comments seemed remarkably callous given the federal government’s painstakingly slow response to Puerto Rico’s suffering. Cruz has had to repeatedly insist Puerto Rico is facing a humanitarian crisis in light of Trump understating the gravity of suffering facing the islanders.

“You are incapable of fulfilling the moral imperative to help the people of PR. Shame on you!” she said.

Trump has not only remarked the island’s death toll numbers don’t reflect that of a “real catastrophe,” he’s also said Puerto Rico’s plights are throwing the U.S. budget “out of whack.”