MEXICO CITY (Reuters) - Mexico is waiting for the United States to prove imported genetically modified (GM) corn is safe for Mexicans, said Deputy Agriculture Secretary Victor Suarez on Wednesday, as a dispute between the two countries plays out under an international trade pact.

In a written submission to a panel of the United States-Mexico-Canada Agreement, Mexico, the top buyer of U.S. corn, argued that science proves GM corn and the herbicide glyphosate are harmful to human health and its native varieties, and that its decree to ban GM corn for human consumption is within its right.

The submission was dated January 2024 but was shared publicly on Tuesday by the nonprofit Institute for Agriculture and Trade Policy.

Suarez said the onus is now on the United States to show GM corn is not harming Mexico's population, which consumes a higher amount of corn than many countries through daily diet staples like nixtamalized dough and tortilla.

The United States "argues that the decisions in Mexico are not based on science and that their decisions are," Suarez told Reuters in an interview. "But we still haven't seen the science of the United States or the companies. We are looking forward to that study with great pleasure."

A spokesman for the U.S. Department of Agriculture said Mexico's approach to biotechnology runs counter to "decades' worth of evidence demonstrating its safety."

A senior official for the U.S. Trade Representative said, "Scientific authorities, including in Mexico, have consistently found biotech products like corn to be safe over a period of decades."

Genetically modified corn is widely used to fatten livestock around the world, though some consumers are more wary of consuming GM products in general. The trade dispute with Mexico could threaten U.S. corn sales at a time when low demand for the commodity and plunging prices are hurting farmers.

Companies like Bayer in recent decades have spent hundreds of millions of dollars developing GM crops and defending the safety of GM foods that are traded around the world.

Mexico's written response cited studies it said showed links between GM corn consumption and glyphosate exposure to liver inflammation in people and impacts to immune response in animals, saying it considers the risk to human health "extremely serious."

The United States in August requested a dispute settlement panel under the USMCA over Mexico's decree to ban GM corn for human consumption, specifically in the use of making flour for tortillas. The decree allows the use of GM yellow corn in animal feed, which accounts for the majority of Mexico's nearly $5.9 billion worth of U.S. corn imports annually.

Washington argues Mexico's decree banning imports of GM corn used for tortillas is not based on science and violates its commitments under the USMCA, which has been in place since 2020.

"There is no impact on trade," Suarez said of Mexico's decree. "The value and volume of exports of GM corn to Mexico has increased."

Mexico's decree also calls for the gradual substitution of GM corn, a point of contention highlighted by U.S. officials.

In its written response, Mexico argued that no specific time frame has been established and therefore it has had no trade impact.

"It is a strategic goal, like the United States would like to have energy sovereignty and energy self-sufficiency," Suarez said.

The United States is expected to issue a rebuttal to Mexico's response.