Mark Bertolini, Chairman and CEO of Aetna, participates in a panel discussion at the 2015 Fortune Global Forum in San Francisco, California November 3, 2015. REUTERS/Elijah Nouvelage/File Photo

NEW YORK (Reuters) - Aetna Inc Chief Executive Officer Mark Bertolini wants a debate about what a “single-payer” healthcare system in the United States would look like, but said he does not think the federal government should run it.

“I think government-run healthcare would be a bad idea,” Bertolini said during an investor conference on Frida. The government’s recent attempt at running healthcare under former President Barack Obama’s healthcare law has not gone well, he said.

As President Donald Trump and Republicans try to repeal and replace the Affordable Care Act (ACA), they are facing off against Democrats like Senator Bernie Sanders of Vermont who not only want to keep it, but move toward a “single-payer system.”

Some Democrats have suggested expanding the government’s Medicare program for people aged 65 and older and the disabled to include more Americans.

Trump has joined the fray, saying at one point that he wanted “healthcare for all” and most recently praising Australia’s system of universal healthcare.

Bertolini said that Americans should discuss what kind of single-payer system is being debated - one in which the government pays for healthcare for more people, or one modeled after the United Kingdom, where the government owns health services providers and manages all aspects of care.

Aetna will not sell any individual plans in the individual marketplace created by the ACA next year after having booked $450 million in losses on the business in 2016.