Sen. Susan Collins said Sunday President Trump is harming Americans by ending subsidies to health insurance companies to offset costs for low-income people.

"What the president is doing is affecting the ability of vulnerable people to receive healthcare right now," Collins, R-Maine, told CNN's Jake Tapper. "These certainly are very disruptive moves that will result in smaller numbers of people being insured. That will make it more difficult [for] low-income people to afford their out-of-pocket costs, and that will destabilize the insurance markets."

Tapper asked Collins if Trump's decision will "hurt American citizens."

"I do believe that," Collins said.

Trump last week announced he will stop paying the subsidies to health insurers, known as cost-sharing reduction payments, intended to reduce deductibles and co-payments for low-income people.

Critics have suggested without the government's subsidies, insurers could increase premiums or leave the insurance marketplaces.

Trump encouraged Congress to devise legislation to extend the subsidies, which were not authorized by Congress under the Affordable Care Act.

Collins earlier this year helped defeat GOP legislation to repeal and replace parts of Obamacare.

On Friday, she announced she would stay in the Senate and not run for governor of Maine, which had been the subject of speculation in recent weeks.