Puerto Rico is facing a critical deadline in its fiscal crisis on Tuesday, as the U.S. territory could default if it does not make a $355 million payment due this week.

If the commonwealth fails to make the payment on bonds issued by its financing arm, the Government Development Bank (GDB), it would likely result in lawsuits and further uncertainty among investors, which in turn would further complicate Puerto Rico's efforts to settle its $72 billion in debt, Reuters noted.

Most of the payment owed on Tuesday, $273 million, falls under what is known as a "general obligation" (GO) and is protected by the island territory's constitution, the newswire detailed. Any default on this portion of the debt would likely need to be settled in the courts, Reuters added.

But those affected might also sue over the non-GO portion, a creditor told the agency.

"It would be really messy," the unidentified source predicted.

The GDB, which is responsible for managing Puerto Rico's heavy debt and says it cannot hope to repay, has come under increasing scrutiny in the meantime, The New York Times reported. A governor appointed by Franklin Roosevelt founded the bank in 1942 to foster development at a time when the commonwealth was known as "the Poorhouse of the Caribbean."

Today, however, the GDB has what the New York newspaper dubbed "tremendous powers" and is charged with advising the island's government on transactions; vetting and restructuring bond deals; holding public money in trust; borrowing funds for government agencies; lending money to those agencies; and financing private enterprise, the publication enumerated.

"You're really not going to find any similar entity in any state," said Melba Acosta Febo, the president and chairwoman of the bank, who is now counting on congressional intervention to help Puerto Rico climb out of its debt crisis.

"We need Chapter 9," Acosta said in reference to the bankruptcy chapter used by cities and other local governments, which is currently unavailable to the commonwealth. "Give us the tool and we will finalize what we are doing."