DES MOINES, Iowa (AP) — U.S. Sen. Bernie Sanders reiterated criticism of Republican efforts to repeal the Affordable Care Act to a receptive crowd in Iowa on Saturday, calling a bill moving through the Senate "disastrous."

The Vermont senator highlighted his thoughts on the bill while blasting Donald Trump, claiming the Republican president has not kept a promise to work for the middle class and to deliver a bill that provides health care for all.

"Donald Trump lied," he said, later adding the president is supporting "the most anti-working class legislation ever presented."

Sanders' remarks, delivered to a large group of community organizers in Des Moines, marked his first time back in the state since the 2016 presidential election. The independent, who almost secured the Democratic nomination for president, made similar comments earlier this month in West Virginia.

Hours earlier inside the same building complex, senior White House counselor Kellyanne Conway told a conservative audience that repealing and replacing former President Barack Obama's 2010 health care law was needed to stabilize the health care insurance market.

"That's not just keeping a campaign promise, it's a moral imperative," she told people attending the Family Leader's annual Family Leadership Summit.

Trump focused on the Senate bill in his latest weekly address, claiming it would expand health care options and drive down costs.

The GOP-controlled Congress has failed to pass legislation through both chambers to repeal the law. Senate Majority Leader Mitch McConnell has delayed an August recess in part to try to pass a proposal. But Republicans have a slim majority in the Senate, and some moderates in his party have expressed reservations.

The nonpartisan Congressional Budget Office estimated an initial bill backed by McConnell would lead to 22 million additional people uninsured if enacted. The office is expected to release its analysis of a revised bill early next week, including a provision supported by Texas Sen. Ted Cruz that would allow the sale of bare bones health insurance policies. Major insurance groups have said the provision is "unworkable in any form."

U.S. Sens. Charles Grassley and Joni Ernst also addressed the conservative audience in the morning, though neither brought up health care. Sanders later asked the Iowa senators in his speech to reject the proposal.

"I beg of them," he said. "Please vote no on this legislation."

Roughly 1,100 people gathered to hear Sanders address the Iowa Citizens for Community Improvement Action Fund convention. He touched on issues that raised his political profile and nearly gave him a win in the first-in-the-nation caucus state: income inequality, the high costs of a college education and the need for more civic engagement. He also pushed back on voter identification laws that he said suppress voting.

It's unclear how much of Sanders' progressive agenda will show up next year as Democrats seek to regain majority control of Congress in the 2018 midterm elections. A closely-watched special election in Georgia for a House seat didn't produce a Democratic win despite the party spending millions in the race.

It's also unclear whether Sanders, who lost the Democratic nomination to Hillary Clinton, will seek higher office again. The senator remains popular within his base, though Democrats may try to push for fresh faces. Sanders will be 76 in September.