By Bill Briggs, NBC News contributor

NBC -- Veterans and their families on the brink of homelessness can access more than a half billion in new federal dollars, the U.S. Department of Veterans Affairs announced Tuesday, as the agency nears its own deadline to pull all veterans off the streets.

The VA will make available $300 million during the 2014 fiscal year – and another $300 million in 2015 – to nonprofit groups that serve low-income veteran families that are currently housed but are on the verge of losing their shelters, VA officials said.

"Those who have served our nation should never find themselves on the streets, living without hope," VA Secretary Eric Shinseki said in a prepared release. "These grants play a critical role in addressing veteran homelessness by assisting our vital partners at the local level in their efforts.

"We are making good progress towards our goal to end veterans' homelessness, but we still have work to do," Shinseki said.

The VA initiative receiving that $600 million injection is called Supportive Services for Veteran Families (SSVF), and it gives qualified veterans in immediate financial jeopardy a secure roof above their heads plus access to VA health care. SSFV is one of several big-money VA investments to help bring in veterans who otherwise live under bridges, in cars or parks. 

federal census released Nov. 21 showed 57,849 veterans were homeless last year – a tally the Obama administration has pledged to drive to zero by the end of 2015. Since 2010, that federal push has cut the count by 24 percent.

Advocates for homeless veterans welcomed the additional millions but questioned what share will wind up paying for overhead at nonprofits that partner with the VA.

"Don't get me wrong, this is great. But out of that $300 million (in 2014), how much of that do you really think will make it to the vets?" asked Joe Leal, who runs the Vet Hunters, a group of veterans who use their military skills to find homeless ex-service members, then urge them to seek shelter, linking them to jobs, mental-health and substance-abuse professionals. Leal says every dollar donated to his all-volunteer team goes to veterans in need.

"People ask me all the time: ‘Joe, do you think we're going to end homelessness in 2015?' I know we are trying. We want to move on and tackle the next problem. But do you know what that means when the VA says they want to end it by 2015? You're asking (anti-homelessness groups) to work themselves out of a job, out of existence."

Through his on-the-ground outreach in Los Angeles, Leal said he's encountered dozens of veterans who were housed temporarily through SSVF but landed back on the streets because they could find only low-paying jobs ($8 to $9 an hour) and ultimately could not afford their rent.

Meanwhile, Leal has also met, he said, dozens Iraq and Afghanistan veterans so physically or emotionally damaged by war they can't work, yet they have been waiting months for the VA to formally classify their service-related disabilities and, ultimately, compensate them – a list of thousands better known as the VA backlog.

"I hope this doesn't come off as negative. But people need to tell the truth, tell what the real obstacles are so that (Americans) don't think there's one cookie-cutter solution to all this," Leal said. "I want people to hear these things so maybe somebody higher up can say: ‘You know, he's right.'"