President Trump hosts a reception for U.S. House and Senate leaders and Cabinet members in the State Dining Room of the White House in Washington on Jan. 23. (Ron Sachs/European Pressphoto Agency)

PHILADELPHIA — Republican leaders laid out an aggressive legislative agenda Wednesday that would have Congress repeal major portions of the Affordable Care Act, pass replacement measures and embark on a major tax code overhaul, all within the first 200 days of blanket GOP control in Washington.

In an afternoon session at an annual GOP policy retreat, House Speaker Paul D. Ryan (Wis.) and Senate Majority Leader Mitch McConnell (Ky.) unveiled plans that put repealing and replacing the Affordable Care Act as the first order of business, with the target date for action within the next three months. Lawmakers also plan to move quickly on a broad rewrite of the tax code that is expected to include deep cuts in tax rates. The agenda sets a vigorous pace in an attempt to make good on key campaign promises made by President Trump.

The leaders laid out a three-pronged plan — one that would start with a special “reconciliation” bill that could skirt a Senate filibuster but accomplish only some of the GOP’s health-care goals. Meanwhile, the Trump administration would be using its executive and regulatory powers to undermine the Obama-era law, while lawmakers started work on more thorough replacement legislation that would need some Democratic support.

In recent days, Trump has pledged to pursue the repeal and replacement of the Affordable Care Act at roughly the same time. “The same day or the same week … could be the same hour,” Trump told the New York Times this month. Lawmakers pressed leaders for more details on how quickly Ryan and McConnell would be able to move on replacement measures and how far those early efforts would go.

Leaders left key details of that plan for a more in-depth session on health care that has been scheduled for Thursday morning.

Tax reform would follow on an ambitious schedule, members who attended the briefing said, with an eye toward passing that major overhaul before Congress breaks for its summer recess in August. Again, details were left for a subsequent session, although Ryan told members that they would work toward a tax reform plan that would cut rates while roughly maintaining current revenue levels.

“He laid out a very ambitious agenda,” said Rep. Charlie Dent (R-Pa.). “We’re on an aggressive timetable; it was almost like a construction chart the way he laid it out.”

Aides warned that it is possible that the Senate will need more time to complete its work on tax reform, but leaders were eager to set an aggressive target.

A senior House appropriator, Rep. Harold Rogers (R-Ky.), announced plans to pass a special appropriations bill funding a Mexican border wall sometime in the spring, and Congress would act to undo several major Obama-era regulations in the meantime. Also on the agenda: drafting the first all-Republican budget in a decade, funding the government and avoiding a debt-ceiling crisis.

One point of tension between Trump and lawmakers was on an infrastructure bill. Leaders told the crowd that the initial draft of their legislative agenda did not include any measure to boost transportation projects, but that Trump himself has insisted on it. No details, such as a price tag or structure, were discussed, multiple members said.

“Without the president’s input, that would not have been the case,” said Rep. Chris Collins (R-N.Y.), who advised the Trump transition.

McConnell also stressed that legislation typically moves much slower in the Senate than it does in the House. Dent said McConnell explained that most major legislation needs 60 votes to pass under long-standing Senate rules. There are 52 Republicans in the Senate, meaning any significant bill would need the support of at least eight Democrats.

Some House members worried that the legislative agenda relies too heavily on a quirk in the Senate rules that allows budget-related legislation to pass with a simple majority, according to several lawmakers who were present for the panel but requested anonymity to speak candidly about the private meeting. Republican leaders plan to use that loophole to repeal major portions of the Affordable Care Act and pass some elements of a replacement. Most other measures will be subject to the 60-vote requirement.

“The speaker’s message was: None of this is going to be easy,” Collins said.

Leaders hope to kick-start the agenda next week when the House is scheduled to start voting to halt Obama-era regulations, including measures related to mining and methane gas emissions from oil and gas production.