MEXICO CITY -- The U.S. State Department and other global leaders on Tuesday denounced the slaying of another environmental leader in rural Honduras, adding to mounting concern of ongoing violence against environmentalists in Latin America.

Honduran President Xiomara Castro confirmed the murder of Juan López on Saturday in the rural Caribbean region of Colón, where a number of environmental advocates battling mining projects have been killed in recent years. Castro called his death a “vile murder” and promised to investigate the slaying.

“I express my solidarity with his family, colleagues and friends. Justice for Juan López,” she posted on X.

López was shot and killed in the municipality of Tocoa after spending years fighting mining companies to protect the region's rivers and forests , according to Human Rights Watch. Few other details were immediately made public by authorities.

Three activists from his same organization, Network Against Anti-Union Violence (RedContraVA), lost their lives last year .

Before his death, López had been given protection by Honduran authorities and the Inter-American Commission on Human Rights because he had received multiple death threats.

On Tuesday, Brian A. Nichols, assistant U.S. secretary of state for Western Hemisphere Affairs, joined Castro and other Honduran leaders in demanding justice for López.

“I strongly condemn the murder of Juan López, a courageous environmental advocate and municipal councilor in Honduras, and call for a thorough and transparent investigation,” he wrote on X.

His remarks were echoed by similar condemnations from the United Nations, which on Tuesday urged “competent authorities to conduct an immediate, thorough and impartial investigation to identify and punish the individuals responsible, both those who carried out the act and those who instigated it.”

Latin America is the most dangerous region in the world for environmental activists, according to the non-governmental organization Global Witness, which monitors the killings of environmentalists. Last year, Colombia, Brazil, Honduras and Mexico were identified as the deadliest regions for defending the environment.

At least 140 environmentalists were killed across these four nations, accounting for 71% of the total number of environmental defenders slain worldwide, according to the organization's report released last week. Honduras, significantly smaller than the other countries on the list, accounted for 18 of those killings.

The Central American nation has been sounding the alarm for years over the number of environmental activists killed there.

Honduras gained international attention when environmental and Indigenous leader Berta Cáceres was murdered in 2016. The killing continues to cast a shadow over Honduras, as many details of her death remain unresolved.

Environmental leaders often serve as watchdogs in rural regions, becoming unwelcome observers in areas where organized crime flourishes.

They often challenge powerful companies and individuals who seek to profit from resource extraction industries like mining and logging, especially in remote areas of Latin America where the law has limited reach.

This opposition can be deadly for individuals like López, who the U.N. called “a champion of natural resource protection”.