Mexico might pay for a wall, but not the one GOP nominee Donald Trump has been asking for on the campaign trail. 

In response to a flood of Central American immigrants across Mexico's Southern border, many of whom eventually try to enter the United States, many Mexicans are calling for a border fence on the Mexico-Central America border, according to The Daily Mail. This proposal has gained traction despite criticism of a similar proposal from Trump for the U.S.-Mexico border. 

The United Nations estimates 400,000 Central Americans enter Mexico illegally each year. Most are fleeing violence back home and the majority are eventually deported back to those homes, according to Financial Times. However, those immigrants skew the perspective of many in the United States who do not differentiate between illegal immigration from Mexico and illegal immigration from Central America. Net immigration, legal or otherwise, has been effectively zero for the past few years, but many of the Central American migrants in Mexico aim to make it to the United States. When those immigrants are deported from the U.S., they are often sent back to Mexico. 

Mexico has adopted numerous strategies to try to halt the cycle. Mexican President Enrique Peña Nieto recently announced this week that his administration plans to seize a privately managed railroad system that has funneled hundreds of thousands of Central Americans through Mexico — immigrants sneak onto the trains in Central America and ride on top of the cars into Mexico. The efforts have been controversial, with critics ponting to Peña Nieto's criticism of Trump's border wall proposition. 

Over the course of his presidential campaign, Trump has insisted he would erect a border wall to halt illegal immigration from Mexico and he would make Mexico pay for it. Peña Nieto has previously stated such an agreement would "never happen." The pair met in Mexico City in August, where Trump told reporters the two men had not discussed the plan or who would pay for such a wall. However, after a speech Trump gave on immigration that same day in Arizona, in which he reiterated his plan to force Mexico's hand, the pair engaged in a Twitter feud over the proposal.