Washington DC - The US will consider obesity or having children with special needs as reasons to reject immigrant visas, in the latest salvo by President Donald Trump to turn away foreigners.

In a cable sent earlier this month, Secretary of State Marco Rubio asks US embassies to factor in conditions, including obesity, when issuing long-term visas, on the grounds that being obese can "require expensive, long-term care."

It also asks embassies to assess if any dependents have "disabilities, chronic medical conditions, or other special needs and require care" to the extent that the visa applicant could not work.

The memo was first reported by KFF Health News. Its contents were confirmed to AFP by a person who saw it.

Politicians House Speaker Mike Johnson fast-tracks Epstein files vote in abrupt pivot

The US is already one of the most obese countries in the world, tied to factors including diet and lack of exercise.

Around 40% of the US population is obese, with rates on average higher in states that voted for Trump.

The new guidance will apply for people seeking to immigrate to the US and not foreigners on routine short-term visits.

The US has long looked at whether a person would become a "public charge" – relying on government funds – before admitting immigrants, including when Americans seek to bring in marriage partners.

But Trump has been especially zealous in finding reasons to refuse entry as he carries out a sweeping crackdown against migration, one of his signature campaign promises.

"It's no secret the Trump administration is putting the interests of the American people first," State Department spokesman Tommy Pigott said.

"This includes enforcing policies that ensure our immigration system is not a burden on the American taxpayer."

The Trump administration has funded a surge of immigration enforcement in a bid to deport undocumented migrants en masse, even when they have not committed crimes other than immigration violations.