Trump has cast the climate accord as elitist, saying when announcing his decision that he was "elected to represent the citizens of Pittsburgh, not Paris."
The project was originally more ambitious, but that he modified it so as not to affect the plastics industry, which employs 14,000 people in Costa Rica.
Spain will host the COP25 climate summit in December, the UN said on Friday, after Chile abandoned plans to hold it due to deadly anti-government protests.
President Carlos Alvarado has pointed to unemployment as the main concern of his government, and the figures remain high amid a slowdown in the economy.
