In addition to sending troops to help patrol the southern border, the White House could lean on health concerns and deem asylum-seekers a risk for carrying tuberculosis or measles to further curb crossings.

Trump advisers have reportedly been investigating how they could implement Title 42, an emergency law that would allow the United States to block asylum-seekers coming from nations that have an infectious disease present, according to the Wall Street Journal. White House officials have identified measles and tuberculosis, which are deemed growing public health crises in South America, as diseases that could allow the Trump administration to block asylum-seekers.

In 2018, Trump adviser Stephen Miller proposed using Title 42 to block migrants at the border after two children in detention facilities died from the flu. The White House resisted Miller’s suggestion, with Cabinet members and White House lawyers arguing that flu outbreaks were not a serious risk to public health.

But in 2020, during the coronavirus pandemic, Trump officials enacted Title 42, after it was found that higher rates of COVID-19 occurred in detention facilities. Trump’s decision to begin enforcing the section of the Public Health Service Act of 1944 that allowed agents to turn away goods and people on March 13, 2020, angered immigrant activists such as Human Rights Watch.

“Instead of centering public health, the current policy seriously endangers the lives of those in need of protection, who are returned to abuse in their country of origin or to dangerous Mexican border cities where organized crime operatives are known to intentionally target migrants,” Human Rights Watch wrote in April 2021.

The Biden administration first maintained this policy, but dropped the policy in May 2023, coinciding with the end of national emergencies declared during the pandemic.

Currently, there is a historic tuberculosis outbreak occurring within Midwest states. Since January 2024, 67 active cases of the disease have been identified in two counties in Kansas. Since Jan. 1 of this year, there have been 87 cases recorded in Missouri.

However, it is uncertain if it is linked to crossings along the southern border. Public health officials say general risk from tuberculosis and measles remains low. Two deaths were recorded last year related to the outbreak.

Talks of enacting Title 42 come as Trump signed an executive order on his first day that placed new restrictions on asylum-seekers. He justified the move by saying the border is seeing an invasion. The order has been met with lawsuits from the American Civil Liberties Union and other groups. Trump’s advisers say he is seeking to invoke other immigration policies in the scenario that the courts strike down his executive order.  

Title 42 would need the approval of the Health and Human Services secretary before it could be enacted. Robert F Kennedy Jr. is currently being appointed to this role.