According to this source:
Peru’s Congress announced Friday it overwhelmingly approved a 10-year moratorium on imports of genetically modified organisms in order to safeguard the country’s biodiversity.
It is always useful to look beyond a country's (or a person's) stated reason for an action for the real motivations. Peru says it wants to ban imports of GMOs to protect biodiversity. I notice they didn't point to health or safety concerns - probably because the World Trade Organization has already ruled that such issues were not a valid trade barrier for GMOs (see here for the WTO ruling in relation to the US-EU debate more than a decade ago).
So, if it isn't really about biodiversity (or only partially about biodiversity), what is motivating Peru's actions? Here I can see two possible (additional) motives at work. The first, is that this is a standard non-tariff trade barrier. Peru can't slap a standard tariff on corn and soybean imports without running afoul of international trade laws. But, they can protect their domestic producers (at the expense of domestic consumers) by putting other trade restrictions in place that limit competition from international producers (Argentina and Brazil are big, nearby growers of GM corn and soybeans) . The second is alluded to in the above story. Peru is apparently a large exporter of organics. The cost of maintaining segregated supply chains increases with a larger GMO market. So a non-tariff trade barrier helps Peru maintain a relative advantage in international trade.
I raise these issues because there will no doubt be some anti-GMO activists who emerge to say things like "see even countries like Peru have decided GMOs are too risky for human health and the environment." But, as you can see the motives are far more complicated than that.