Protesters demonstrate outside of the White House in Washington, D.C., Dec. 5, 2015. Reuters

Mayors and county executives all over the country urged President Barack Obama Thursday to take additional steps to protect immigrants before he leaves office. Thirty-one officials sent Obama a letter on behalf of Cities for Action, a national immigration advocacy coalition, thanking him for his previous actions and outlining additional policies he should implement.

“As mayors and county executives in the Cities for Action coalition, we write to thank you for your leadership on behalf of immigrant families and urge you to take action to ensure continued support for vulnerable immigrants in our communities before you leave office,” the letter read.

The letter thanked the president especially for his repeal of NSEERS, a post-9/11 Muslim program that required men from predominantly Muslim nations to register with the federal government upon their arrival in the United States. The program hasn’t been actively used since 2011 but the repeal was intended to make it more complicated for a future Donald Trump presidential administration to launch its own registration system rather than just revive an existing one.

Obama has deported more undocumented immigrants than any president in history. Around 2.5 million people have been deported in the years from 2009 to 2015, according to the Department of Homeland Security. While campaigning, Trump said he planned to deport three million undocumented immigrants.

Among the recommendations suggested to Obama were a stronger system for the Deferred Action for Childhood Arrivals program (DACA), which provides authorization to work and a stop to deportation of undocumented immigrants who arrived as children. Around 740,000 undocumented immigrants have work permits under DACA, according to Politico. Trump suggested on the campaign trail he would alter or eradicate the program while.

“I want dreamers to come from the United States. I want the people in the United States that have children, I want them to have dreams, also,” the then-candidate said at a press conference in February. “We’re always talking about dreamers for other people. I want the children that are growing up in the United States to be dreamers, also. They’re not dreaming right now.”

In December, however, Trump said he would “work something out” for children under DACA. “They got brought here at a very young age, they’ve worked here, they’ve gone to school here,” he added.

The letter also urged Obama to support immigrants who cannot return to their home country by reviewing Temporary Protected Status applications faster, extending designations and issuing new designations.