One day after Gov. Charlie Baker revealed Massachusetts has only received a fraction of the ventilators it requested from the national stockpile, the state's congressional delegation slammed the federal response as "grossly insufficient."

Both senators and all nine representatives urged the Federal Emergency Management Agency to fulfill the Baker administration's request for about 1,700 ventilators, warning in a letter that hospitals in Massachusetts are on the verge of exhausting the life-saving equipment they have available.

"We have heard from hospitals in the state that they will run out of invasive ventilators in a matter of days and will run out of other ventilators that can be adapted for use for COVID-19 patients within a week," lawmakers wrote.

"Given the growing need in Massachusetts, approving and sending only 100 ventilators to Massachusetts is grossly insufficient, and FEMA can and must do more to help Massachusetts during this crisis," they continued.

Many state leaders across the country have been at odds with Washington over the federal response to the coronavirus pandemic, voicing frustration with the amount of resources that have flowed from the Strategic National Stockpile and — as Baker did — with being outbid in their efforts to purchase protective equipment.

One week ago, Baker announced Massachusetts would receive more than 1,000 ventilators from the stockpile by the end of the first week in April, which he described as "a big positive step forward in the right direction."

However, on Sunday, the governor said only 100 ventilators had arrived so far.

"We believe that the process as it's been laid out to us is going to be an incremental one," Baker told reporters. "We don't believe this is the last shipment. We fully expect that we'll get additional ventilators over the course of the next two weeks."

But at this point, it's unclear how many ventilators will arrive and when they will arrive.

During remarks on Sunday night, President Donald Trump mentioned the 100 ventilators sent to Massachusetts, as well as 600 sent to Illinois, 300 to Michigan, 200 to Louisiana, and 500 to New Jersey.

"At the same time, Governor Inslee — we appreciate this — of Washington State has returned 400 ventilators, which can now be deployed elsewhere in our country," Trump said, according to a White House transcript. "So the State of Washington has done very well. They won't be needing some of the ventilators that have been sent — about 400. That's a lot. And we appreciate that he's able to give them back. He feels confident that they are in good shape for the coming weeks, until we can declare a final victory."

Trump also said that thousands of ventilators are "under construction."

On Saturday, Trump said the federal government was a "backup" for states on the supply front.

"I mean, look, we had one state asking for 40,000 ventilators," he said. "Think of it: 40,000. It's not possible. They won't need that many, and now they're admitting they don't need that many. But we're getting as many as we can to them."

In its letter, the delegation described a higher request in Massachusetts for about 1,700 ventilators and reiterated Baker's projections that peak hospitalizations could hit between April 10 and April 20, with anywhere from 47,000 to 172,000 infections over the course of the outbreak.

Lawmakers said five other states have received equipment in recent days. The stockpile, they said, "currently has over 9,000 total ventilators available" and could receive another 2,000 from the Department of Defense.

"In order to address the shortage of ventilators in Massachusetts, and to prevent the catastrophic effect a shortage will have on hospitals, patients and communities across the Commonwealth, we ask that you immediately grant requests submitted by Massachusetts and provide needed ventilators to the state," they wrote.

The delegation also asked FEMA to provide more information by April 15 about why Massachusetts only received a fraction of its initial request, whether the agency disagrees with state projections about needed capacity, and whether federal officials would help connect Massachusetts leaders to external sources of supplies.

As the pandemic spreads, most of the world faces challenges trying to acquire enough ventilators to save lives and enough personal protective equipment to keep front-line health care and public safety workers safe from spread of the highly infectious virus.

Public officials have discussed distributing gear on a priority basis, directing it first to states at or near the peaks of their outbreaks and then asking those who are within capacity to help out others.

In a Friday memorandum to Massachusetts hospitals, the Department of Public Health urged hospitals to prepare now to deploy additional pieces of equipment toward the fight against COVID-19.

Health care facilities should "immediately identify any anesthesia ventilators, transport ventilators, and noninvasive ventilators in their organizations that can potentially be used for COVID-19 clinical management, ensure they are in proper working order, ensure they are available to use for the care of patients who need ventilator support, and ensure there are adequately trained staff to operate these resources," the DPH wrote, as quoted in a Monday newsletter from the Massachusetts Health and Hospital Association.