WASHINGTON (Reuters) - U.S. President Donald Trump on Monday slammed Puerto Rico's governor and blasted the U.S. territory's leaders, accusing them of wasting billions of dollars of hurricane disaster relief aid as protests swelled across the island.

Asked if Puerto Rico Governor Ricardo Rosselló should resign, Trump said he was terrible. The Republican president also criticized San Juan Mayor Carmen Yulin Cruz.

"You have totally grossly incompetent leadership at the top of Puerto Rico," Trump told reporters at the White House. "The leadership is corrupt and incompetent."

Thousands of protesters on Monday continued to call for Rossello's resignation following offensive chat messages, the latest turmoil to hit the bankrupt territory, which had already been struggling before Hurricane Maria hit in 2017.

Democrats and others have criticized the Trump administration over its response to the storms, which led to nearly 3,000 deaths.

In June, U.S. lawmakers backed legislation to boost disaster recovery efforts across the country, including in Puerto Rico. Trump initially opposed sending any more aid to the Caribbean island, but recently relented.

On Monday, Trump again questioned the Puerto Rican government's handling of any aid, saying it was "in the hands of incompetent people, and very corrupt people."

"The money is squandered and wasted and stolen," he told reporters. "Congress is not happy about it."

(Reporting by Roberta Rampton; Writing by Susan Heavey; Editing by Jonathan Oatis)