The development bank is important because it orchestrates most of Puerto Rico’s complex web of debt, and because it has the increasingly difficult job of making sure all branches of government have adequate cash. There are concerns that if it ran into severe problems, they would spread to other parts of the government.

And on July 1, so many debt payments are due that the officials said that without relief, there would be defaults from the top to the bottom of the hierarchy of creditors. When questioned further, they said it was still too soon to reveal how much relief they would seek from each creditor group.

Under the ground rules for the briefing, the officials could not be identified by name or quoted directly.

On Wednesday, the United States Treasury secretary, Jacob J. Lew, is scheduled to visit Puerto Rico. He is expected to discuss the island’s debt crisis with Gov. Alejandro García Padilla, senior members of the legislature, and business, labor and community leaders.

Mr. Lew and other Obama administration officials have been urging Congress to enact measures they say would help it restructure its $72 billion of debt in an orderly manner. In particular, the administration has argued that Puerto Rico needs access to a legal framework, like bankruptcy, that would automatically stay creditor lawsuits and make it possible to force dissident creditors to accept settlements. As currently written, the bankruptcy code bars Puerto Rico’s cities or other bodies of government from using Chapter 9, the provision that insolvent cities and counties on the mainland have been able to use to shed debt.

Republicans in Congress have held back from agreeing to amend the bankruptcy code for Puerto Rico, saying they must first have a better understanding of how the island got into so much trouble.

The officials who briefed journalists on Monday said that any restructuring would be easier if they could do it under the protective shield of bankruptcy — but that even without bankruptcy they had to press forward. They said debt relief was the only hope for bringing the government’s fiscal affairs into balance over the long term.