The USNS Comfort and Javits Center field hospital remained mostly empty Friday — as emergency rooms teemed with coronavirus patients and federal and state officials blamed each other for the vacancies.

By end of day, there were only 270 patients being treated inside the 1,000-bed Javits, which is dedicated to recovering COVID-19 patients. That’s just slightly better than the 225 patients there a day prior.

And there were only 62 patients, including 26 in intensive care, on the 500-bed Comfort medical ship, which is dedicated to the sickest COVID-19 cases, an occupancy rate that remained virtually unchanged for a second day. By Saturday night, the ship had treated 100 patients.

Meanwhile, Big Apple hospitals were jammed with 20,400 patients, according to city data.

The logjam is caused by overly strict admission criteria, frustrated medical staffers say.

“It’s insufferable that these guys are not taking our patients, because we need places to put these people,” a doctor at Metropolitan Hospital Center told The Post of the lingering vacancies at the Javits and Comfort.

“We’re sending people home that we wouldn’t have six months ago, because there’s no room for them,” said the doctor, who asked to remain anonymous.

“We’re right at the breaking point, and we’re not being helped. I don’t know why these guys are playing these games.”

Last week, the two federal facilities drafted lists of their capabilities with the help and oversight of the state-contracted Northwell Health hospital system.

Both the feds and state contributed to the admissions criteria — but now each blame the other for overly strict initial rules, which officials on each side claim are being relaxed.

For example, only patients who were ambulatory and who required minimal nursing — one nurse visit every eight hours — were being admitted to Javits.

“It required a patient be stable enough to be almost discharged,” the Metropolitan doctor said.

Both facilities already have built-in limitations.

The Army medics-staffed Javits came online to treat recovering COVID-19 patients on April 2 — with no operating rooms and a limited ICU that’s designed to stay partially empty, as a reserve for any patients who may relapse.

The facility cannot, therefore, accept patients already intubated or whose underlying conditions — heart disease, for instance — could require surgery, defense officials explain.

The Navy medics-staffed Comfort, meanwhile, is a repurposed battle-injury hospital that therefore has no pediatric, OBGYN or mental-health capabilities.

The ship came online for COVID-19 cases on Monday — and only on Wednesday was much equipment delivered by copter.

Both facilities only accept transfers from other hospitals, and if patients are already intubated, moving them and their ventilator can be risky.

President Trump, meanwhile, said both the Javits and Comfort are success stories.

“It is incredible the job they did,” he said Friday when asked about the low occupancies. “But they are using less beds. This is a good thing, not a bad thing . . . The death numbers are horrific, but if you go back now and you are finding they are going to start to come down substantially based on the fact the bed usage of the number of beds are much, much less. much, much less.”

Additional reporting by Bob Fredericks