WASHINGTON — Tom Price was sworn in as U.S. secretary of health on Friday, putting in place a determined opponent of Obamacare to help President Donald Trump fulfill his pledge to dismantle his predecessor’s law and reshape the country’s health care system.

As head of the Department of Health and Human Services, Price has the authority to rewrite rules implementing the 2010 Affordable Care Act, also known as Obamacare. He could move quickly to rework the regulations while waiting for Republicans in Congress to keep their pledge to scrap the law entirely.

The Republican president signed an order on Jan. 20, his first day in office, to freeze regulations and take other steps to weaken the law enacted by former Democratic President Barack Obama, a directive that will fall largely on Price. But Trump said in a recent Fox News interview that a replacement for the law may not come until next year.

Trump said on Friday the effort was a “difficult process” but could now get going with Price in place.

“Now we get down to the final strokes,” he told reporters at a separate news conference at the White House alongside visiting Japanese Prime Minister Shinzo Abe. He did not offer more details but said the country would end up with “tremendous health care at a lower price.”

Republicans, who have long viewed Obamacare as federal overreach and who have the majority in Congress, are trying to craft a replacement but have not agreed on one. Twenty million Americans gained health insurance under the law.

“Having Dr. Tom Price at the helm of HHS gives us a committed ally in our work to repeal and replace Obamacare,” said U.S. House Speaker Paul Ryan, who has vowed to pass a new plan this year.

Price, a member of the House since 2005 who chaired the budget committee, offered legislation in 2015 to repeal Obamacare and replace it with age-adjusted tax credits for the purchase of health insurance.

While Price’s fellow Republicans have controlled the House since 2011, they did not advance his bill and it was not considered by the full chamber.

The Senate voted 52-47 earlier on Friday to approve Price, a former orthopedic surgeon, to oversee the department. Maine’s senators split, with Republican Susan Collins voting for him and independent Angus King opposing him.

Price’s nomination was dogged by questions about his trading in hundreds of thousands of dollars in health company stocks while working on health care legislation. Democrats accused him of making misleading statements. Price defended his actions.

Democrats also criticized Price for his opposition to Obamacare, his ideas about restructuring the Medicare program for the elderly and disabled, and his opposition to Planned Parenthood, an organization that provides abortions and other affordable health care and education services.

In a statement, Collins spokeswoman Annie Clark said that the senator thinks having a medical doctor in charge “will be very helpful” and “while she does disagree with Dr. Price on some issues, she looks forward to working alongside him to help increase access to affordable health insurance for all Americans.”

But King, who caucuses with Democrats, has been a chief defender of Obamacare and gave a nearly half-hour floor speech against Price late Thursday before the vote, saying that many of the 75,000 Mainers enrolled in the program couldn’t get coverage without it.

“That’s wrong in Maine and I can’t vote for somebody who’s going to put a dagger in the heart of these citizens of Maine,” he said. “I cannot do it. My conscience won’t let me.”

With Price confirmed, the Senate is expected to vote on Monday on Trump’s U.S. Treasury secretary-designate, Steven Mnuchin.

BDN writer Michael Shepherd contributed to this report.