An unflattering portrait of US President Donald Trump will be removed from a state government building after his tirade against it.

The offending oil painting, which was installed in 2019, is displayed alongside those of other US presidents in Colorado’s State Capitol.

Trump took to Truth Social to fume about artist Sarah A Boardman’s portrayal, which he said was “truly the worst”.

“Nobody likes a bad picture or painting of themselves, but the one in Colorado, in the State Capitol, put up by the Governor, along with all other Presidents, was purposefully distorted to a level that even I, perhaps, have never seen before,” he complained.

“The artist also did President Obama, and he looks wonderful, but the one on me is truly the worst.”

Trump took personal aim at Boardman, claiming she must have “lost her talent as she got older”.

“In any event, I would much prefer not having a picture than having this one,” he wrote.

Trump claimed that “many people” from Colorado had called and written to complain about the portrait.

“In fact, they are actually angry about it!” he said.

Later on Monday (Australian time), House Democrats said that unflattering portrait would be taken down at the request of Republican leaders in the legislature.

“If the GOP (Republican Party) wants to spend time and money on which portrait of Trump hangs in the capitol, then that’s up to them,” the Democrats said.

Colorado Republicans raised more than $US10,000 ($A15,876) through a GoFundMe account to commission the oil painting.

Trump’s rant drew comments online, with Republicans Against Trump calling him “such a petty, insecure baby”.

X user Alexandra Marshall suggested that the portrait “looks nothing like him”.

Another X commentator Sam Stein posted: “Absolutely dying. Both that Trump is so clearly bothered by this that he couldn’t resist posting about, and at how objectively bad the portrait is.”

Trump said he would speak to Colorado’s Democrat Governor Jared Polis to demand the picture be taken down.

Polis’s office said he was “surprised to learn Trump was an “aficionado of our Colorado state capitol and its artwork”.

“The state capitol was completed in 1901, and features rose onyx and white Yule marble mined in Colorado, and includes portraits of former presidents and former governors,” it said.

“We appreciate the President and everyone’s interest in our capitol building and are always looking for any opportunity to improve our visitor experience.”

Boardman did not immediately respond to a request for comment from The Associated Press.

She previously told The Denver Post that it was important her depictions of both Obama and Trump looked “apolitical”.

-with AAP