The American Medical Association waded into the immigration debate Wednesday with a letter to the U.S. Department of Homeland Security asking the agency to clarify how the Trump Administration's executive order applies to health workers trained abroad, to those seeking to train in the U.S. and to patients needing care.

It is "vitally important" that this process not impede patients' access to timely treatment or restrict doctors and international medical graduates "who have been granted visas to train, practice, or attend medical conferences" in the U.S., " the AMA's chief executive officer, Dr. James L. Madara, wrote in a letter to Homeland Security Secretary John F. Kelly.

Madara note that the order could block entry to foreign medical graduates who have applied for or who have been granted visas to come to the U.S. to train and provide care in poor and underserved communities to "some of our most vulnerable patients," many of whom live in rural and low-income areas.

"One of every four physicians practicing in the United States is an [international medical graduate]," he said, noting that they meet the same stringent licensing requirements as U.S. graduates, but they are more likely to practice in underserved and poor communities, and to fill training positions in primary care and other specialties that face significant workforce shortages.

The letter, sent to reporters via email, requests rapid action, because the order places into limbo foreign medical school graduates whose residency assignments will be decided next month. He also expressed concerns about how the order might affect medical school applicants granted temporary work permits under an Obama Administration program that allows certain undocumented immigrants who entered the U.S. as minors to remain for at least two years.