US President Donald Trump's immigration policies could "disrupt the flow of scientific ideas and knowledge", according to an article in a leading medical journal.

The authors say the first few weeks of Mr Trump's presidency have raised "worrying questions about its likely impact on science and health policy".

Many of the new administration's pronouncements seem "lacking in careful consideration of the consequences for biomedical research, healthcare, and ultimately the health of people in the US and the rest of the world", according to the paper published in the British Medical Journal (BMJ).

Ashish Jha KT Li, professor of health policy at Harvard TH Chan School of Public Policy, Jose Merino, the US clinical research editor for the BMJ, the journal's executive editor Kamran Abbasi and Elizabeth Loder, its head of research, said the Trump administration's policies "risk head-on collision with the scientific and health communities".

They wrote that they were concerned that the administration was "acting in ways that will suppress research and limit communication on scientific topics that it deems politically inconvenient".

"Restricted" departmental communications to the public, accessibility of scientific information on government websites and changes proposed to the US Food and Drug Administration were highlighted as other areas of concern.

The authors added: "His immigration policy will disrupt the flow of scientific ideas and knowledge, hinder recruitment of scientists to American institutions, limit training opportunities for international physicians, and worsen national shortages of healthcare workers."

The repeal of the Affordable Care Act, also known as Obamacare, could prove damaging without a viable alternative, they added, and funding cuts to international health organisations and global health projects "will harm women and worsen the health of vulnerable populations".

"Any president of the United States is entitled to implement policies that reflect personal ideology and political beliefs," the authors wrote.

"The public may disagree on the merits and drawbacks of these policies, but as long as the supporting arguments are based on facts and comply with constitutional principles then so be it.

"In its first weeks, however, Donald Trump's presidency has raised worrying questions about its likely impact on science and health policy.

"Many of the new administration's pronouncements seem to place little value on facts or analysis.

"They also seem lacking in careful consideration of the consequences for biomedical research, healthcare, and ultimately the health of people in the US and the rest of the world."