Detailing an increasingly desperate situation in Venezuela, the United Nations made a confidential plea on Wednesday to the country’s two rival leaders to end a political battle over humanitarian aid that has blocked shipments of food and medicine.

A copy of a report delivered to representatives of both sides, obtained by The New York Times, casts no specific blame for worsening a crisis in Venezuela that by some estimates has plunged nearly the entire population of 32 million into poverty.

But it suggests that measures carried out by the government of President Nicolás Maduro, such as blockading Venezuela’s borders and imposing restrictions on aid organizations, have made the crisis more acute, as have sanctions put in place by the United States and others.

The report also suggested that Mr. Maduro’s antagonist, Juan Guaidó, the opposition leader, also had seized on aid deliveries to try to gain the upper hand, exacerbating tensions by forcing a confrontation in February in which Mr. Maduro repelled an effort to puncture the blockade.

This use of the human suffering as a political weapon by both sides is the greatest impediment to improving conditions for Venezuelans, the report said.

“The politicization of humanitarian assistance in the context of the crisis makes delivery of assistance in accordance with the principles of neutrality, impartiality and independence more difficult,” the report said.

As much as anything, the United Nations document reads like an entreaty for a country on the brink of ruin.

As much as 94 percent of the population lives in poverty, according to the report, and up to seven million people, or a quarter of Venezuela’s population, are now in need of humanitarian assistance in a country that was once one of the world’s wealthiest.