President Donald Trump has nominated Amy Coney Barrett to fill the Supreme Court seat vacated by the death of Justice Ruth Bader Ginsburg.

Ms Barrett, a judge on the Chicago-based 7th US Circuit Court of Appeals and a devout Roman Catholic, has been hailed by religious conservatives and others on the right as an ideological heir to conservative stalwart Antonin Scalia, the late Supreme Court justice for whom she clerked.

But liberals say her legal views are too heavily influenced by her religious beliefs and fear her ascent to the nation's highest court could lead to a scaling back of hard-fought abortion rights.

President Trump hailed Ms Barrett as "a woman of remarkable intellect and character", saying he had studied her record closely before making the pick.

"I looked and I studied, and you are very eminently qualified," he said as Ms Barrett stood next to him in the Rose Garden.

While Democrats appear powerless to stop Ms Barrett's confirmation in the GOP-controlled Senate, they are seeking to use the process to weaken Mr Trump's re-election chances.

Ms Barrett's nomination could become a reckoning over abortion, an issue that has divided many Americans so bitterly for almost half a century.

The idea of overturning or gutting Roe v. Wade, the landmark 1973 decision that legalised abortion, has animated activists in both parties for decades.

At just 48, Ms Barrett would be the youngest justice, and her tenure could last for decades.

In a speech at Notre Dame University, she previously said: "...if you can keep in mind that your fundamental purpose in life is not to be a lawyer, but to know, love, & serve God, you truly will be a different kind of lawyer."