A former White House photographer has attacked Donald Trump's response to Hurricane Harvey, pointedly sharing a picture of Barack Obama consoling a flood victim to highlight the contrast between the two presidents.

Pete Souza posted online an image of the Democrat hugging a distraught woman in New Jersey as he toured areas devastated by Hurricane Sandy in October 2012.

It comes after Mr Trump was criticised for not meeting victims during a trip to flood-stricken Texas, where he marvelled at the size of a crowd watching him speak but offered no solace those affected.

During the visit to Corpus Christi this week the President wore a $40 cap for sale on his website, prompting accusations he was using the disaster to promote his own merchandise.

"At a time like this, it shouldn't be about selling baseball hats or commenting on crowd size. It's about helping our fellow human beings," wrote Pete Souza, former chief official White House photographer to Mr Obama and Ronald Reagan, an in Instagram post.

"This storm is catastrophic, not epic. Thousands of people are affected," he added, referring to a word used repeatedly by Mr Trump to describe the scale of the floods and boast about his administration's response.

"It's historic. It's epic, what happened, but I will tell you it happened in Texas and Texas can handle anything," the President said this week while waving the state's flag.

He added: "We want to do it better than ever before. We want to be looked at in five years, in 10 years from now as this is the way to do it. This was of epic proportions. Nobody’s ever seen anything like this."

Trump arrives in Texas to reassure Harvey victims and marvel at crowd sizes

Mr Trump was due to make a second visit to Texas on Saturday to survey storm damage and speak to residents and volunteers in Houston, the city hit hardest by flooding. He was also set to visit Lake Charles, Louisiana.

The White House said the President had previously steered clear of the worst devastation to avoid disruption recovery operations.

But his remarks in Corpus Christi - where he exclaimed "what a crowd, what a turnout" during an impromptu speech - raised eyebrows.

"There was a lot of high-fiving about how well this disaster was being handled even as people were on their rooftops hoping to be rescued," said David Axelrod, a top adviser to President Obama.