New figures released by the Department of Housing and Urban Development on Thursday showed that 564,708 people were homeless on a night in January of this year, a 2 percent drop from 2014. 

HUD officials said the decline, of a total of 11 percent since 2007, is an encouraging sign that the Obama administration is succeeding in its five-year-old goal of preventing and ending homelessness and ending what the government calls chronic homelessness by 2017.

The so-called point-in-time count in cities across the country on one night 10 months ago also showed persistent challenges for some populations to find permanent homes, including veterans, children and young adults and the chronically homeless.

The count found 180,760 homeless youth under age 25, including 127,787 who were under 18. About 37,000 were children without parents, the data showed.

The Department of Education, however, has said the numbers are going up. according to advocacy groups that say the agency counted more than 1.3 million children and youth in a survey during the 2013-2014 school year, a 3.4 percent jump from the year before.

The HUD count, done by volunteers who fan out across major cities every year, looking under bridges, in parks and other known encampments for the homeless, records the number of people who are in shelters or living outside. But it does not count those who double up with families and friends for short spurts or longer durations, leading advocates to question whether the government is able to accurately gather information on the problem.

HUD officials said they are working to improve strategies for counting homeless youth. Although the count for this population was slightly lower in 2015 than in the previous year, officials cautioned against comparing year-to-year data. They said they are still working on ways to accurately count young people and want to explore more use of social media and of housing advocates who have direct relationships with young people.

Housing officials conceded that they will not reach the administration's goal of ending veteran homelessness by the end of the year, but pointed to progress in helping a population that has long struggled with homelessness.

The data released Thursday puts the number of homeless veterans across the country at just under 48,000 in January, a drop of 2,000 from a year earlier and more than 27,000 since 2010.

"The value of having these kinds of urgent and ambitious goals is that it drives more progress than we ever would have achieved otherwise," Matthew Doherty, executive director of the Interagency Council on Homelessness, said at a news conference with HUD officials to announce the numbers. "As we get closer to that goal date, we're seeing that level of urgency and action in communities."