President Trump is promising Guatemala that if its legislature signs off on a “Safe Third Country” agreement to accept asylum seekers who come to the United States, he will increase the number of H‑2A temporary agricultural work visas for Guatemalans. His Acting Secretary of Homeland Security Kevin McAleenan was down in Guatemala promising Guatemalan legislators that the United States will “double or triple” the 4,000 H‑2A visas that Guatemalans received in 2018.

This is a very important conceptual shift from this administration. Increasing legal immigration options to prevent illegal immigration should be the government’s single‐​minded focus right now. But the administration appears to be making promises that it cannot deliver. H‑2A visas already have no numerical limit, so there are no visas or cap space to “hand over” to Guatemalans.

Businesses need a reason to hire Guatemalans, and the administration has not yet provided any new incentive to do so. A small adjustment in the H‑2A rules for Guatemalans could provide that incentive.

In 2018, Mexicans received 92 percent of all H‑2A visas, while Guatemalans received only 2 percent—or 3,936. For comparison, Border Patrol is on pace to apprehend more than 200,000 Guatemalans this year. The reason that nearly all H‑2As go to Mexicans is because foreign workers cannot apply directly for a visa. Employers must first recruit and sponsor them, and right now, businesses are almost exclusively recruiting H‑2A workers from Mexico.

Employers prefer Mexican H‑2A workers for several reasons. Mexico is closer, so some employers can bus workers to their worksites, which is cheaper than flying workers in from other countries. Mexican consular officials operate under the belief that Mexicans are less likely to overstay their visas, so they deny visas to Mexicans about half as often as they deny them for Guatemalans. This effectively means that employers need to recruit twice as many Guatemalans to get the same number of workers here.

But the most important reason is that H‑2A recruiters are already operating in Mexico. The marginal cost of expanding recruitment there is virtually zero, while transitioning to a new country would require new investments. There is simply no reason for them to move to Guatemala, and the Trump administration so far has not provided any reason for them to do so.

Moreover, the increase in H‑2A visas for Mexicans has played a major role in decreasing illegal immigration from Mexico, so it would not benefit the United States to encourage employers to stop hiring Mexicans in favor of Guatemalans.

So what can the government do? Right now, the H‑2A program only allows employers to hire workers for “seasonal” positions. The H‑2A law bans year‐​round jobs, which are a majority of all agricultural jobs, and include entire industries like dairies and livestock. Cows need milking the entire year, so the dairy industry cannot use the H‑2A visa. The government should offer a waiver of the seasonality requirement for H‑2A workers from Guatemala.

This change would require congressional action, but fortunately, there is already bipartisan support for waiving the seasonality requirement. Rep. Dan Newhouse (R‑WA) and Rep. Henry Cueller (D‑TX) have managed to insert into the Department of Homeland Security appropriations bill an amendment removing the seasonality requirement for all countries, not just Guatemala, in each of the last three years.

Unfortunately, the GOP Senate has so far not agreed to the amendment, and Congress has left it out of the full government funding bills. Perhaps with a border crisis and the White House’s prodding, this could change. But for it to reduce illegal immigration or benefit Guatemala, Congress would need to limit the change only to Guatemalans. The president’s desire for a Guatemalan deal could encourage him to prod Congress to do so.