House Speaker Nancy Pelosi questioned whether a health-care proposal embraced by several Democratic presidential candidates would be too expensive and fail to provide the same coverage as the Affordable Care Act.

Instead, Pelosi (D-Calif.) suggested Thursday that she would rather build on the 2010 law and is yet to be convinced the Medicare-for-all proposal pushed by many liberals would achieve its purported goals.

“I’m agnostic. Show me how you think you can get there,” Pelosi said in an interview with The Washington Post. “We all share the value of health care for all Americans — quality, affordable health care for all Americans. What is the path to that? I think it’s the Affordable Care Act, and if that leads to Medicare-for-all, that may be the path.”

She also suggested that Medicare-for-all had become more of a buzzword among political activists in the run-up to the 2020 campaign, a loosely defined concept that few people understood in concrete terms.

“When most people say they’re for Medicare-for-all, I think they mean health care for all. Let’s see what that means. A lot of people love having their employer-based insurance and the Affordable Care Act gave them better benefits,” said Pelosi, who shepherded the ACA through Congress in 2009 and 2010 in her first speakership.

Her comments come as President Trump abandoned plans to press for a vote on a bill to replace the increasingly more popular ACA, often called Obamacare, ahead of next year’s election, as Republicans have had little appetite to take on an issue that benefited Democrats politically.

Pelosi’s remarks served as the strongest words of caution from a senior Democrat about a policy proposal that is serving as an ideological fault line on the campaign trail and among her own caucus. Republicans also have sought to use Medicare-for-all as a cudgel against the Democrats.

Medicare-for-all, once seen as a far-off hope of Sen. Bernie Sanders (I-Vt.) in his 2016 ­presidential campaign, is now the focus of legislation co-sponsored by more than 100 House Democrats. Rising stars such as Rep. Alexandria Ocasio-Cortez (D-N.Y.) have linked arms with veteran liberals in the caucus to promote the legislation.

Sanders is again touting Medicare-for-all in his second presidential bid, this time followed by other top contenders such as Sens. Kamala D. Harris (D-Calif.) and Elizabeth Warren (D-Mass.) who have expressed support for the plan.

But Republicans, and more-cautious Democrats, have warned that the proposal would end the health-care plans of 180 million Americans whose insurance coverage comes from their private employers, most of whom like their current plans.

Just days after announcing her bid, Harris had to backtrack from a comment that she was ready to “move on” from private insurance and “eliminate all of that.”

Pelosi said Thursday that there would need to be a long runway to move toward Medicare-for-all and that the ACA is a key mechanism to starting a national insurance plan. “I don’t think you can say, ‘Let’s get rid of the Affordable Care Act so we can have Medicare-for-all,’ because you can’t get to Medicare-for-all unless you have some of the resources of the Affordable Care Act,” she said.

“So we’ll have hearings, again, let’s see what it is. Right now it’s a $30 trillion price tag. What do people get for that in terms of care, and what do they pay for that along the way?”

Pelosi this year promised the leaders of the Congressional Progressive Caucus hearings on ­single-payer health care in the Rules and Budget committees, but liberal lawmakers want more and have lobbied her for hearings in the powerful Ways and Means Committee — and even a floor vote — leading to frustration in some corners.

“I, myself, am more concerned about getting a vote for Medicare-for-all,” Ocasio-Cortez told reporters last week.

Liberal leaders have also confronted Pelosi about her top health-care staffer, Wendell Primus. In meetings with health industry officials, Primus has opposed the idea of Medicare-for-all, according to reports at the Intercept and Politico.

Pelosi defended her veteran staffer in the interview. “Wendell is not a member of Congress; Wendell is probably the most progressive staff person on Capitol Hill,” she said, noting that Primus left the Clinton administration “because they passed the so-called welfare reform bill, which I voted against.”

One liberal House leader, Rep. Ro Khanna (D-Calif.), viewed Pelosi’s comments as more of a “challenge” than a dismissal. He said Pelosi is “just being pragmatic” and is “absolutely right” that Medicare needs to be improved to include things like dental and vision insurance and long-term care.

Khanna also agreed that liberals need to make the case to voters that Medicare-for-all is good for the country, predicting that they will in this Congress — and that Pelosi will eventually give them a floor vote on the idea. “I believe we will meet the high bar that Nancy Pelosi has set,” he said. “We can make the case.”

Pelosi has powerful allies in her bid to focus the party on the ACA, not Medicare-for-all. Last month, she orchestrated a meeting between the massive class of freshman Democrats and former president Barack Obama, who cautioned members about the price tag associated with some of the “bold” policy ideas popular in their ranks.

Obama didn’t specifically name Medicare-for-all, but people in the room said his warnings were clearly aimed at the proposal. He argued that such policy ideas could require tax increases, and he urged members to think carefully about those costs and be transparent about them with voters.

At a low political moment in early 2010, as some Obama advisers recommended pulling back from the ACA, Pelosi served as the leading advocate to go full speed ahead and pass the law.

It is her greatest legislative accomplishment in either tenure as speaker, but the ACA was unpopular nine years ago and contributed to the 2010 midterm debacle in which she lost the majority. Last year, after Republicans failed to repeal the law and it grew more popular, Pelosi rallied Democrats around the ACA and its protections for essential benefits, leading to a net gain of 40 seats and the majority.

On Thursday, Pelosi said Medicare as it exists does not provide enough coverage and would need to undergo a costly overhaul before it could replace many of the private insurance plans.

“Medicare is not as good a health benefit as the Affordable Care Act,” she said. “So, if you are to do Medicare-for-all you have to improve the package — and when you improve the package, you have to have more money.”