WASHINGTON — Migration from Central America, which has caused U.S. officials to start deportation raids recently, won’t slow down without increased investment in the region, El Salvador’s ambassador to the United States said Wednesday.

“Without stability, there can be no substantial security,” Ambassador Francisco Altschul said at an Inter-American Dialogue event. “Without stability, the flows of regular migration won’t be stopped.”

Between October and December 2015, the number of unaccompanied children crossing the southern border into the U.S. was 17,370, up 117 percent from the same period the previous year. All but 3,107 of the children came from Guatemala, Honduras, and El Salvador.

Congress recently approved a $750 million plan to fund social and economic projects in Guatemala, Honduras, and El Salvador, which was less than President Barack Obama had requested. The aid follows two waves of undocumented immigrants from Central America arriving to the U.S. over the past two years.

And there’s no sign of the numbers slowing down just yet. According to data released by U.S. Customs and Border Protection Tuesday, the number of Central American undocumented families and unaccompanied children grew significantly late last year.

“This has to be a longer effort and there has to be an ability to maintain attention and commitment to this that exceeds one political party or administration,” said Mark Lopes, United States executive director of the Inter-American Development Bank.

Manuel Orozco, a senior fellow at Inter-American Dialogue, a research group, said that a new development strategy will only reduce mass migration if it overhauls the current economic model.

“The economic growth model in Central America is pretty much unsustainable,” Orozco said. “It’s not one that brings opportunity.”

Orozco’s research showed that an undiversified economy, ecosystem of violence and close family ties with immigrants contributed to the lack of development in Central America. He also said the region is “desperate for ideas” on how to be innovative.

Orozco and Altschul said that any change and development created through the U.S. aid will take at least a decade to show.

“We’re not talking about the short-term,” Altschul said. “So we need to create institutions that make it possible for change to continue.”