Muni bonds expert: Here's what Puerto Rico needs

Puerto Rico should take a page out of New York City's playbook in order to turn around its financial mess, municipal bonds expert Alexandra Lebenthal said Thursday.

"You need to bring in a financial control board, like you had in New York City in the 1970s — somebody who comes in and says, 'We're going to take the tough steps that need to happen to structurally change the whole country,'" the CEO of Lebenthal Holdings told CNBC's "Squawk Box."

In 1975, New York state created the Municipal Assistance Corp. to oversee the city's finances and issue bonds at a time when the nation's biggest city was on the verge of bankruptcy.

Puerto Rico, mired by more than $70 billion in debt and a rapidly declining population, will most likely default on its debt payment due Jan. 1, Gov. Alejandro Garcia Padilla said Tuesday.

"It is very, very unlikely there is no default," Garcia Padilla said. "Very unlikely. In full or part."

The tropical island first defaulted on its debt in August and has warned that more defaults are coming.

— Reuters contributed to this report.