In one of the biggest 2018 premium hikes sought to date, Iowa’s only ObamaCare insurer is looking for a 57 percent rate increase – that’s 13 percent more than they asked for just two months earlier.

It’s a troubling trend that’s been spreading across the country as jittery insurers stay stuck in a holding pattern waiting on Congress and the Trump administration to decide the fate of the Affordable Care Act.

President Trump has at different times encouraged lawmakers to let ObamaCare implode, pushed his party to repeal and replace the bill, admonished his own party for failing to do so and supported a repeal-only bill.

One of the president's biggest complaints about the ACA has been the trend of rising premiums in the insurance exchanges. But insurers have only accelerated that push in the face of Trump threats to cut off billions in federal funding meant to keep co-pays and deductibles down, coupled with congressional deadlock and market uncertainty over the repeal of ObamaCare.

In June, Iowa's Medica sent a letter to its customers explaining it was seeking a 43.5 percent rate hike, affecting about 14,000 Iowans. The company spelled out the steep premium increases but offered customers assurances that federal subsidies would shield most them from forking over thousands more a year.

Since then, however, Medica has revised the proposed hike to 57 percent – citing once again uncertainties over federal health care subsidies.

“We remain hopeful the federal government will fund the cost-sharing reductions, but we are working with the Iowa Insurance Division to help consumers understand the implications of lack of this funding,” Geoff Bartsh, Medica vice president of individual and family business, said in a statement. “We regret the disruption this creates for consumers.”

Last month, Trump tweeted his frustration at the Senate’s inability to pass legislation that would kill ObamaCare. Repealing and replacing the country’s health care law was an “easy” promise Trump repeatedly made on the campaign trail.

“If a new HealthCare Bill is not approved quickly, BAILOUTS for Insurance Companies and BAILOUTS for Members of Congress will end very soon!” the president tweeted.

On Wednesday, the Trump administration announced it would make its August subsidy payments to health insurers. Insurers receive the money under ObamaCare to cover costs related to the law’s requirement to offer plans with reduced deductibles and copays.

A day earlier, the Congressional Budget Office released a report that said ObamaCare premiums would rise 20 percent and the federal deficit would increase by $6 billion next year if Trump followed through with his threat to stop payments.

Andrew Bates, a spokesman for the progressive advocacy group American Bridge, isn't mincing words on who's to blame.

"Make no mistake: this 57 percent spike in premiums is a direct result of Donald Trump and Mike Pence sabotaging the Affordable Care Act marketplaces," Bates told Fox News. "Now Iowa families are going to suffer the consequences."

Medica is hardly the only insurer seeking a big rate hike; many are looking for double-digit increases next year.

Several big-name insurers like Humana, UnitedHealth Group and Anthem have bolted from some states altogether, while others like Medica are trying to protect their profits by passing on the cost to their customers -- and taxpayers who cover premium subsidies.

In states where big insurers are staying – like Idaho, West Virginia, South Carolina and Wyoming – some companies are looking to hike premiums by 30 percent or more for ObamaCare plans in 2018.