By Kevin Liptak and Tami Luhby, CNN

(CNN) -- President Donald Trump promised Americans their insurance options would improve after he signs an executive order loosening restrictions on buying policies across state lines.

Speaking in the Oval Office Tuesday, Trump said he'd likely sign the order this week. Precise details of the measure aren't yet known, but Trump has previously previewed unilateral action that would make it easier for small businesses to buy coverage by joining together.

"I will be signing something probably this week which is going to go a long way to take care of people that have been so badly hurt on health care," Trump said ahead of a meeting with Henry Kissinger, the former secretary of state.

"They will be able to buy across state lines. They will get great competitive health care and it will cost the United States nothing," he said.

Stalled in his efforts to repeal and replace the Obama-era Affordable Care Act in Congress, Trump vowed late last month to take executive action to change aspects of the law, which he has deemed a failure. The plan has drawn backing from legislators like Sen. Rand Paul, the Kentucky Republican who has identified specific reforms that could be made by the President alone.

Trump described his executive order as "very simple in one way, but intricate in another."

He said people would be able to buy plans from "many, many competitors," which he implied would drive down prices.

"We will have to do something with Obamacare because it's failing," he said, gesturing to his 94-year-old guest. "Henry Kissinger doesn't want to pay 116% increase and that's what's happening and it's getting worse by the minute."

What the order would do

The executive order's main provision likely aims to make it easier for small employers to buy insurance through so-called association health plans, which are usually sponsored by trade organizations or interest groups. For instance, small plumbing firms in different states could band together to form a group and buy coverage.

The directive will call on federal agencies to amend the rules governing these plans to free them from state regulation, according to a Wall Street Journal report on Saturday. Instead, the nationwide plans would be subject to the same federal oversight as large-employer policies.

These plans do not have to adhere to all of Obamacare's provisions, such as the requirement to provide comprehensive policies that cover prescription drugs, mental health and substance abuse, according to Kevin Lucia, project director at Georgetown University's Health Policy Institute.

The switch could also allow association plans to deny coverage or set rates based on the medical history of those in the group, so plans with younger, healthier members could offer lower premiums.

Supporters say this would increase competition and allow people to buy more affordable coverage across state lines.

Critics, however, say that widening access to these plans would likely draw younger, healthier consumers away from the Obamacare individual and small business exchanges, which would raise the rates of policies sold there. Also, these plans have a long history of financial troubles, with some becoming insolvent.

Trump is aiming to use his executive powers to give more Americans access to cheaper health insurance plans, a key Republican goal. But association health plan policies would likely provide skimpier coverage since they would not have to adhere to all of Obamacare's protections.

Plus, the planned changes would likely further destabilize the Affordable Care Act by siphoning younger and healthier consumers into less-expensive options, leaving sicker and older Americans in the exchanges and driving up their rates.

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