President Trump is making it clear he's willing to browbeat Republican senators who don't support the healthcare bill that GOP leaders hope to vote on next week.

Five Republicans have said they don't like the bill as is, and on Saturday, Trump accused the holdouts of being in the way of dismantling Obamacare.

"I cannot imagine that these very fine Republican senators would allow the American people to suffer a broken ObamaCare any longer!", he tweeted. The president also attacked former President Barack Obama's often-used line to sell his signature healthcare law, a promise that Americans can keep their health plan, which Politifact dubbed 2013's "Lie of the Year."

"Democrats slam GOP healthcare proposal as Obamacare premiums & deductibles increase by over 100%. Remember keep your doctor, keep your plan?" Trump said.

Trump tried a similar approach in the House, but conservatives there ignored him and held out to make the bill tougher. Trump celebrated passage of that bill, but then later, when it hit the Senate, he said it was "mean."

Though the Senate's healthcare draft bill maintains some of the elements of the House-passed bill, for instance rolling back Obamacare's taxes and phasing out Medicaid expansion, it also isn't as drastic as the House version in some areas, including in how it provides additional funding to stabilize the Obamacare health insurance exchanges.

The Senate draft bill faces an uphill battle as five GOP senators — Mike Lee of Utah, Ted Cruz of Texas, Rand Paul of Kentucky, Ron Johnson of Wisconsin and Dean Heller of Nevada — say they will not vote for the bill in its current form. Only two can vote against it if the 52-member Republican majority hopes to pass the legislation under the process of budget reconciliation, capped with a tie-breaking vote from Vice President Pence, which would allow the leadership to avoid a Democratic filibuster.

Whether Trump's implicit threats will make headway with the Republican holdouts is yet to be seen, but on the surface the bill would need to get tougher if it were to win over the likes of hardline conservatives like Lee.

And reportedly the bill is already moving in that direction. Vox reported Saturday that revisions to the Senate bill could add a provision that would lock out from the individual market, for six months, for people who try to game the system by not maintaining consistent coverage. That could complicate the voting process, however, as the report notes the change may not qualify for reconciliation.

Trump's supporters are also backing him by getting ready to attack opponents of the bill. A political nonprofit aligned with Trump, America First Policies, confirmed to the Washington Examiner that it is readying a million dollar attack campaign against Heller for opposing the healthcare proposal.

On Thursday, Trump went all in for the Senate bill, but signaled that there is still work to be done to perfect it. "I am very supportive of the Senate #HealthcareBill. Look forward to making it really special! Remember, ObamaCare is dead," he tweeted.

In a Fox News clip of a "Fox & Friends" interview to air Sunday morning, Trump admitted that it is a "very complicated" process to pass healthcare legislation. "Healthcare's a very complicated subject from the standpoint that you move it this way, and this group doesn't like it. You have a very narrow path," he said, adding "honestly, nobody can be totally happy, even without the votes."