MANILA, Philippines (AP) — The Philippines is the only Asia-Pacific country where the rate of teen pregnancies rose over the last two decades and the slow decline of its overall fertility rate may deprive the country of the faster economic growth expected in places that have more working-age people than younger and older dependents, the U.N. Population Fund said Thursday.

Girls aged 15 to 19 make up 10 percent of the country's population of 100 million and one out of 10 of them have already given birth, UNFPA country representative Klaus Beck said. That fertility rate in that age group is 57 births for every 1,000 girls as of 2013 — higher than rates found by surveys every five years from 1998.

He emphasized the urgency of fully implementing a reproductive health law, investing in quality education and health services for teenage girls, and increasing jobs for youth.

The cost of not finishing high school education over the lifetime of young people would be equivalent to about 1 percent of the country gross domestic product, he added.

The study supported by UNFPA found that "due to the slow reduction in the fertility rate the country may not be able to benefit fully from the demographic dividend," or the balance of its population among children, working-age adults (age 15 to 65) and elderly. It said the window of time to reap economic benefits from the favorable demographics was closing fast.

The Philippines' total fertility rate was 3 births per woman as of 2013, falling at a slow pace of 1.6 percent per year from 7 births per woman in 1960. But the poorest quintile of the population has a higher fertility rate of 5.2 births per woman as of 2013.

"With the right policies and investments in human capital, countries can empower young people to drive economic and social development and boost per-capita incomes," Beck said.

Economic Planning Secretary Ernesto Pernia said the administration of new President Rodrigo Duterte will ensure quality education for the youth and full implement of the reproductive health law that guarantees universal access to methods of contraception, sexual education, and maternal care. The Supreme Court ruled the law was constitutional in 2013 but a year later it banned dispensing of subdermal implants, a popular birth control method because it is long-term and safe for breastfeeding women.

Pernia said the government aims to reduce poverty by 1.25 percent to 1.5 percent each year, and a big push for that would be to reduce the number of children among the poorest people, citing surveys that show those couples have more children than they wanted.