Former Vice President Joe Biden said on Sunday he “can’t promise” individuals will be allowed to keep their existing doctors if his new public option healthcare proposal is implemented.

Biden, who was instrumental in helping President Barack Obama pass the Affordable Care Act (ACA), made the admission to the Washington Examiner while campaigning in Nevada.

“Well look, I can’t promise — I can promise them that if in fact the private insurance they have is kept by their company, they keep whoever that plan allows,” Biden told the outlet. “That’s all I can promise.”

This week, Biden unveiled his healthcare plan, which seeks to fortify ObamaCare, while simultaneously expanding access to coverage. The crux of Biden’s proposal revolves around creating a new “public health insurance option” that will function similar to Medicare and Medicaid.

When announcing the plan, which is estimated to cost $750 billion over the first ten years alone, Biden attempted to paint it as a more realistic alternative to the Medicare for All supported by the more liberal 2020 Democrats. To help sell his proposal, the former vice president is accusing his opponents of wanting to scrap the ACA, one of the few legislative achievements of former President Barack Obama.

“I believe we have to protect and build on ObamaCare. That’s why I’ve proposed adding a public option to ObamaCare as the best way to lower costs and cover everyone,” he said in a video announcing the plan. “I understand the appeal of Medicare for All, but folks supporting it should be clear that it means getting rid of Obamacare, and I’m not for that.”

In pushing his plan for a public option, Biden appears to have learned from the failures Obama made with the ACA. The former president most notably damaged his public standing and the perception of the ACA by pledging early on that “if you like your health care plan, you can keep it.” The promise turned out to be impossible because many existing health insurance plans did not meet the strict regulations and standards created by ObamaCare. Although it is impossible to know how many plans were canceled, some have reported the number as being upwards of four million plans.

It is noted, however, that the former vice president’s refusal to promise individuals can keep their existing doctors stands in stark contrast to the one he made on Monday to a forum of AARP voters in Iowa.

“If you like your health care plan, your employer-based plan, you can keep it,” Biden said, adding that “if you like your private insurance, you can keep it.”