By Erin Mershon and Lindsey McPherson/CQ Roll Call

Reps. Fred Upton of Michigan and Billy Long of Missouri, the most high-profile holdouts on the Republican health care overhaul, are meeting with President Donald Trump Wednesday morning to discuss a policy change that could bring them on board with the plan.

Their meeting also included Energy and Commerce Chairman Greg Walden of Oregon, and Rep. Michael Burgess of Texas, who chairs the health subcommittee on that panel, according to Majority Whip Steve Scalise of Louisiana and several GOP aides. Up for discussion is an extra $8 billion in funding that aides say is aimed at helping people with pre-existing conditions.

“We’ve been working with them and a number of other members to continue growing the vote, and we’ve been successful so far,” Scalise said of the White House meeting with the four Republicans.

Speaker Paul D. Ryan told conservative talk show host Hugh Hewitt on Wednesday morning that Upton is leading the charge on the changes, noting he is trying to be “constructive in improving this bill so that people who were currently undecided feel better about supporting this bill.”

“His amendment that he’s working on is something that people, nobody has a problem with,” Ryan said. “And it’s actually helping. Fred Upton identified something that he thinks will make the bill better that is mutually agreed to by people from all parts of our conference.”

Ryan cited a host of players who have been involved in the negotiations, including Trump, Vice President Mike Pence and his staff, and House Freedom Caucus Chairman Rep. Mark Meadows.

“What we’re doing is listening to our members, finding where that sweet spot of consensus is, and driving there,” he said.

Ryan declined to say when he’ll be ready to announce a vote on the bill.

“We’re going to bring them up with we get the votes,” he said. “We’re getting extremely close. We’re having very, very productive conversations with our members. … And so I feel very good about the progress we’re making, and we’ll make the announcement when we make the announcement.”

Winning over Upton, a former Energy and Commerce Chairman and a leader on the party’s health care policy, and Long, a key Trump ally, could have much broader significance for the House’s efforts to pass their health care package this week.

Their defections this week swelled the ranks of “no” votes to at least 21, and Republicans can only lose 22 votes and still pass the measure. At least a dozen other members have told CQ Roll Call they remain undecided this week.

Upton and Long both balked that the Republican package under consideration because they do not believe it goes far enough to protect people with pre-existing conditions, a concern shared by many other moderate holdouts.

Republican leaders have argued that the $115 billion over 10 years in the package for both state and federal high risk pools, which help insurers offset the costs of covering sicker Americans who could be charged higher prices for insurance under the current bill. The extra $8 billion would supplement that pool.

A White House official said the House members were meeting with Trump.

— Joseph Williams and John T. Bennett contributed to this report.