President Donald Trump opened his Oval Office address on 8 January with these words: “There is a growing humanitarian and security crisis at our southern border.” In one respect, he’s right. There is a growing humanitarian crisis at the border, but not for lack of a border wall – the crisis is growing because of the Trump administration’s illegal and inhumane policies toward asylum seekers.

As a law student enrolled in the Immigrants’ Rights Clinic, I spent the first week of the new year volunteering in Tijuana with an organization that provides legal services to asylum seekers. The organization, Al Otro Lado, serves individuals who hope to present themselves to US officials at the port of San Ysidro, the largest land border crossing in the United States. I use the word “hope” because the Trump administration has effectively prevented thousands of people – including many women and children – from exercising their legal right to apply for asylum by blocking their path to the port of entry itself.

Under domestic and international law, any immigrant who arrives at a US port of entry has a right to apply for asylum. The process is not easy and involves multiple interviews to determine whether an individual meets the narrow, categorical definition of a “refugee” under US law. Many asylum seekers will languish in detention while awaiting their turn before an immigration judge, without any opportunity to collect evidence or consult an attorney. Most will have their applications denied. But everyone is entitled to this process. The government must allow families at the border to present themselves and claim asylum.

Immigrants who arrive at the Mexican entrance to San Ysidro sign up for an informal waiting list and take a number. “La Lista” was developed and managed by Mexican immigration officials and others in response to the US government’s policy of allowing only a small number of people to present themselves each day. It is a primitive system, recorded by hand in a composition notebook and relayed only by word of mouth. The numbers are scratched on to tiny pieces of scrap paper, which migrants guard closely as they wait their turn. The wait can take weeks or even months.

This system should not have to exist; the situation that US policies have created is patently illegal and unquestionably responsible for the growing humanitarian crisis at the southern border. I met dozens of families with young children who were living in shelters and tent cities, patiently waiting for their numbers to be read off La Lista. These families had no food, income or access to basic needs like medical care. They expressed fear of street crime and the practical challenges of living without documentation. Those who could work had a disincentive to seeking employment in Tijuana, because any evidence of potential stability in Mexico might hurt their asylum cases in the United States.

Moreover, the administration’s policy of punishing families by making them wait at the border fails to deter migrants, many of whom are fleeing violence and repression from hostile government actors. I advised some families not to approach the border at all. I tried to be realistic about the hardships they would face even after they successfully crossed on to US soil. I will never forget the looks of desperation on the faces of the men and women I counseled. Fathers told me they had to take the chance for their little girls. Rape victims told me they could not return home and face their attackers. They all told me they understood the risks. But what choice did they have?

If President Trump is genuinely concerned with the growing humanitarian crisis at the border, he should take immediate action to permit asylum seekers to present themselves to immigration officials. The law is clear on the issue – immigrants have the right to apply for asylum at any port of entry and between ports of entry. What’s clearer is that his policies have had, and will continue to have, devastating effects on thousands of well-meaning families who have not even begun the long and difficult asylum process.