WASHINGTON, D.C: The United States is to start vetting would-be refugees from Central America in their home countries instead of on American soil, and offer those in imminent danger a temporary haven in Costa Rica, officials said on Tuesday (Wednesday in Manila). The announcement—a significant change in US immigration handling—comes after America toughened its southern border against a persistent flow of thousands of Central Americans fleeing violence, and as it steps up deportations of migrants who failed to win asylum. It also arrives in a US election year in which migration is a hot-button issue. Under the plan, to be carried out in coordination with the UN refugee agency UNHCR and the International Organization for Migration, “the United States government will pre-screen vulnerable applicants from the region seeking protection,” the White House said in a statement. It will focus on citizens of the so-called “Northern Triangle” in Central America comprising Guatemala, El Salvador and Honduras, which are prey to frightening levels of gang-related violence, poverty and corruption.