Former US President Barack Obama is being criticised for reportedly agreeing a $400,000 (£310,000) fee for a speech to a Wall Street bank.

The 44th president has accepted an offer to speak at a healthcare conference hosted by Cantor Fitzgerald in September, US media report.

The deal comes less than 100 days after Obama left office.

In 2009, he told CBS: “I did not run for office to be helping out a bunch of fat cat bankers on Wall Street.”

Obama has reportedly agreed to be a keynote speaker at an event hosted by Cantor Fitzgerald LP, an investment bank that lost more than two-thirds of its staff in the attack on the World Trade Centre on 11 September 2001.

The fee is nearly twice the $225,000 that Hillary Clinton received for three speeches to Goldman Sachs in 2015.

She was heavily criticised during last year’s presidential campaign for her Wall Street speeches, with activists on both sides of the political spectrum demanding she release the transcripts.

During Obama’s two terms as US president he at times seemed to have strained relations with the financial sector, reports the BBC.

He deplored high bonuses paid to bank executives, and said Wall Street shared blame for the 2008 financial crisis.

Some liberals have criticised Obama’s speech decision, with one writer saying it “will undermine everything he believes in”.

The New York Post, meanwhile, said his speech made him “Wall Street’s newest fat cat”.

Obama appears to be enjoying life after the White House since he left office in January.

On Monday he made his first public remarks about community organising to students at the University of Chicago, where his presidential library is set to be built.

He was pictured kite-surfing in February with Richard Branson off the Virgin tycoon’s private Caribbean island.

And just this month, he and former First Lady Michelle Obama were pictured aboard music mogul David Geffen’s luxury yacht off French Polynesia.

They were reportedly on holiday with Bruce Springsteen, Tom Hanks and Oprah Winfrey.

Obama also took in a Broadway play in New York City before dining with U2’s Bono.

Two months ago the former president accepted an offer from Penguin Random House for two books to be written separately by him and Michelle.

They are expected to receive $65m for the deal.