U.S. Sen. Susan Collins, R-Maine, will appear on ABC’s “This Week” with George Stephanopoulos Sunday morning.

Speaker of the House Paul Ryan, R-Wis., will also appear on the show. Ryan led the passage of the American Health Care Act through the House last week. House Republicans and President Trump have said the bill is a major step toward dismantling the Affordable Care Act, also known as Obamacare. The bill has yet to be debated in the Senate, and may go through significant changes.

In a statement following the passage of the bill Thursday, Collins said the U.S. health care system is under stress, but the effect of the House bill was not fully known, including the impact on Maine residents.

“Although I will carefully review the legislation the House passed today, at this point there seem to be more questions than answers about its consequences,” Collins said.

Collins appeared with Sen. Angus King, I-Maine, on “Meet the Press” with Chuck Todd on April 30.

“This Week” airs at 9 a.m.