Donald Trump has warned against rushed appointments of judges before he is inaugurated as sources close to Supreme Court Justice Sonia Sotomayor deny suggestions she should step down to allow her replacement.

Justice Sotomayor, 70, is the third-oldest judge on the nine-member bench and has long been public about living her life with type 1 diabetes.

Trump's impending return to the White House is now lending steam to anxious Democrats calling for her to resign so President Joe Biden has the opportunity to nominate a younger replacement.

But sources tell US media that Justice Sotomayor does not plan to go anywhere.

"This is no time to lose her important voice on the court," one person told the Wall Street Journal, adding that she "takes better care of herself than anyone I know".

“She’s in great health, and the court needs her now more than ever,” a quote given to CNN reads. Sources also told ABC News she has no plans to resign.

The BBC has reached out for comment.

Senator Bernie Sanders on Sunday acknowledged to NBC's Meet the Press that he had heard "a little bit" of talk about Justice Sotomayor being asked to step aside but said calls for her to resign are not "sensible".

No elected Democrats in Washington have called on her to leave her lifetime appointment.

The Puerto Rican jurist, who is the first woman of colour to serve on the court, maintains a busy public schedule and is a persistent questioner during oral argument sessions.

But many liberals around the country remember the death of Justice Ruth Bader Ginsburg in 2020 during Trump's first term.

Justice Ginsburg, known by her admirers as "RBG", died at age 87 as a result of complications from pancreatic cancer.

Her death and the resulting vacancy on the court just 46 days before a presidential election led to a political firestorm and gave Trump the opportunity to make a third lifetime appointment to the highest court in the US.

Trump appointed Justice Amy Coney Barrett, which shifted the court to a six-to-three conservative majority.

That conservative-leaning court has made major decisions - from the 2022 repeal of the nationwide right to abortion to how cities deal with homelessness - that have been felt across the US.

With Trump poised to take over from Biden in January, some Democrats and liberal activists have urged Justice Sotomayor to retire as a precaution.

Her defenders have dismissed the call as ageist, and argue that her health is well managed.

With just over two months until Trump's inauguration, there is little time for Biden to nominate - and for the Senate to confirm - a new justice.

On Sunday in a social media post, the Republican president-elect said "Democrats are looking to ram through their Judges as the Republicans fight" over who will lead their new Senate majority.

Trump may have further opportunities to shape the Supreme Court.

Conservative Justices Clarence Thomas and Samuel Alito are 76 and 74 years old, respectively.

If the Republican chooses both their replacements, he would be the first president since Franklin D Roosevelt to have appointed a majority of justices to the court.

In his first term, Trump also moulded lower courts in the judiciary branch, working with Senate Republicans to name 234 federal judges over the four-year period.