The US Supreme Court has preserved access to a commonly used abortion pill, ruling the drug can remain available while a legal case continues.

In a split decision, it also rejected restrictions on mifepristone implemented by a lower court, essentially maintaining the status quo.

The future of the drug was questioned after a Texas judge sought to invalidate its long-standing approval.

The case could have wide-ranging implications for abortion access.

Mifepristone is part of a two-drug regiment that now accounts for more than half of abortions in the US. It has been used by more than five million women in the country to safely end their pregnancies.

It was first approved by the US Food and Drug Administration (FDA) more than 20 years ago after four years of review.

The FDA placed mifepristone in a select category of just 60 drugs that is regulated under a system of extra restrictions, which are repeatedly re-evaluated.

Its safety and effectiveness is supported by mainstream medical organisations including the American College of Obstetrics and Gynaecologists (ACOG) and the World Health Organisation