Hundreds of thousands of tourists have been left stranded after Boris Johnson refused to grant the collapsed travel firm Thomas Cook a £150 million bailout.
Talks between the United Kingdom government and the 178-year-old company broke down on Sunday, putting 22,000 jobs at risk and triggering the biggest repatriation effort in modern history.
Roughly 600,000 customers of the firm, including 150,000 Brits, have been affected by the collapse.
The company had warned earlier this year that Brexit was causing consumers to put off their holiday plans.
Johnson said on Monday that all UK customers would be brought back, with total costs to British taxpayers expected to total hundreds of millions of pounds.
However, asked about the crisis, the UK prime minister insisted that it would have been wrong to bail out the company.
"It is perfectly true that a request was made to the government for a subvention of about £150m," Johnson told reporters during a flight to the UN General Assembly in New York.
"Clearly, that is a lot of taxpayers' money and sets up, as people will appreciate, a moral hazard in the case of future such commercial difficulties that companies face."
He said that executives at the company must be held responsible for the firm's collapse.
"One is driven to reflect on whether the directors of these companies are properly incentivised to sort such matters out," he said.
The opposition Labour party said the prime minister should have intervened to prevent the firm's collapse.
"To just stand to one side, I just don't think that's wise Government," Labour's Shadow Chancellor John McDonnell told the BBC, adding that he believed that government had an "ideological bias" against any form of state intervention.