US President Donald Trump has unveiled renovations to the bathroom in the Lincoln Bedroom, as his remodelling of the White House continues.

Trump shared photos of the new bathroom on social media, saying it had been "renovated in the 1940s in an art deco green tile style, which was totally inappropriate for the Lincoln Era".

He claimed the new black and white marble is "very appropriate for the time of Abraham Lincoln and, in fact, could be the marble that was originally there!".

It is the latest change Trump has made to the White House this year. In October, its East Wing was demolished to make way for his new multi-million dollar ballroom.

The bathroom is a part of Abraham Lincoln's office and cabinet room, which former President Harry Truman fixed up as a part of his massive renovation of the White House in the late 1940s.

The wallpaper of Lincoln's office and bedroom was once coloured in green and gold, according to the White House Historical Association.

After Trump's remodelling, it now features gold fixtures and accents for the sink, bathtub faucet and shower door, as well as a chandelier.

The White House said the renovation was privately funded at no cost to the taxpayer.

The US president's attempts to put his own stamp on the White House have prompted criticism from conservation groups and his political opponents.

Trump previously said his ballroom addition to the East Wing would not "interfere with the current building". But in October, he said the "existing structure" had to be torn down.

Trump said the ballroom construction was being fully funded by him and "some friends of mine - donors".

Conservationists argued Trump should have sought public review before making the changes, which they say would overwhelm the classical style of the White House.

The White House hit back at its critics, saying "unhinged leftists" were "clutching their pearls over President Donald J Trump's visionary addition of a grand, privately funded ballroom to the White House - a bold, necessary addition".

Other changes to the White House include his decision in August to pave over grass in the Rose Garden with stone, transforming a lawn into a patio.

Trump also added touches of gilded gold all over the Oval Office, including additional portraits framed in gold, gold-framed mirrors and a gold leaf for the presidential seal on the ceiling of the office.

In response to his latest bathroom renovation, the Democrats accused Trump of being more focused on remaking the White House than solving the government shutdown.

Central to the shutdown, which is now entering its second month, is a dispute over whether to extend health insurance subsidies.

"Donald Trump actually cares more about his toilet than he does about fixing your healthcare," Democratic Senate Minority Leader Chuck Schumer wrote in a post on social media.

Speaking at an event on Saturday, former US President Barack Obama said Trump has been "focused on critical issues, like paving over the Rose Garden so folks don't get mud on their shoes and gold plating the Oval Office and building a $300m ballroom" than resolving the shutdown.

"If you can't visit a doctor, don't worry. He will save you a dance," he added.