The Trump administration is expected to change State Department visa guidelines aimed at "birth tourism", the practice of foreign nationals giving birth on US soil to ensure their children become American citizens.

The State Department is amending a regulation to ensure that visitor visas to the US are not used for birth tourism, reports CNN.

The amended rule will be "published shortly," according to a State Department official, who said it is intended to address the national security and law enforcement risks associated with the practice.

Details about the change, how it will be enforced and the impact to travelers were not immediately available.

The Department of Homeland Security and White House referred CNN to the State Department for comment.

Axios first reported the expected change.

The expected announcement comes a week after a Hong Kong-based airline apologised for demanding that a passenger take a test to prove she was not pregnant before boarding a flight to the US Pacific island of Saipan -- part of the US commonwealth of Northern Mariana Islands, which has emerged as a favorite destination for "birth tourism."

The airline said in a statement that it was under pressure from authorities in Saipan to step up checks on passengers.

"We took actions on flights to Saipan from February 2019 to help ensure US immigration laws were not being undermined," the airline said. "Under our new management, we recognise the significant concerns this practice has caused. We have immediately suspended the practice while we review it."

It's not immediately clear whether the incident was related to the US regulatory change.

In July, the commonwealth's House of Representatives passed a resolution seeking to limit birthright citizenship on the islands in the wake of the increased popularity of birth tourism in Saipan.

The US has sought legal action against people thought to be capitalizing on the industry.

Last year, the Department of Justice charged three people with running "birth tourism" companies that catered to Chinese clients in Southern California -- the first time that criminal charges had been filed in a US federal court over the practice.

The charges stemmed from a 2015 raid of dozens of so-called "maternity hotels," often upscale apartments, where mothers-to-be paid between $15,000 and $50,000 to give birth in the US, according to a US Immigration and Customs Enforcement statement at the time.

In 2018, President Donald Trump vowed to end birthright citizenship by executive order, though lawmakers immediately pushed back against his comments.