Donald Trump says he is willing to negotiate with Republican senators to pass controversial healthcare bill

Five Republicans officially don't support the bill in its current form

President Donald Trump (AP)

Donald Trump has signalled that he is willing to work with four Republican senators who have said they’re “not ready to vote” for the Senate’s Obamacare repeal and replacement bill.

Hours after the measure was unveiled to Congress, Rand Paul of Kentucky, Ron Johnson of Wisconsin, Ted Cruz of Texas and Mike Lee of Utah said in a joint statement that they were not ready to vote in favour of the legislation.

“Currently, for a variety of reasons, we are not ready to vote for this bill, but we are open to negotiation and obtaining more information before it is brought to the floor,” the senators said.

Republican leadership is aiming to have a vote on the bill next week before senators leave Washington, DC for the Fourth of July recess.

Mr Trump acknowledged in an interview with Fox News that a lack of support from the four Republicans leaves the party's overhaul of former President Barack Obama's signature healthcare policy on a “very, very narrow path” to victory.

“It's not that they're opposed. They'd like to get certain changes. And we'll see if we can take care of that,” Mr Trump said, calling the group of conservative senators “four very good people”.

But despite the President's apparent willingness to negotiate, another Republican – Dean Heller of Nevada – has also come out against the healthcare measure, saying “it's simply not the answer” and that there isn't anything in the bill that would lower premiums.

“I cannot support a piece of legislation that takes insurance away from tens of millions of Americans,” he said

Mr Heller, like four other GOP senators, left the door open to negotiations. But he said “it's going to be very difficult to get me to a 'yes'” on the bill.

Mr Trump's role is expected to become more pronounced in coming days as the vote nears. Senate Republican leaders may rely on the deal-making former businessman to lean on conservative senators who are balking at the bill.

"We're pleasantly surprised with a lot of the support that's already come out and I think we'll continue to work through [it], in particular the four individuals who have expressed some ideas and concerns," White House spokesman Sean Spicer told reporters at a White House briefing.

The Senate plan significantly scales back Medicaid – a healthcare programme for the poor – and repeals Obamacare’s taxes on the wealthy. Republicans have called Obamacare – officially known as the Affordable Care Act – “unsustainable”, citing skyrocketing premiums and the unstable health insurance marketplaces created by the law.

With a majority of 52 senators, Senate Majority Leader Mitch McConnell can only afford to lose two ‘yea’ votes on the bill. No Democrats, who have lambasted the healthcare measure as “heartless”, are expected to support it. In the event of a 50-50 tie, Vice President Mike Pence would cast the deciding vote.

The four Republican holdouts, among the Senate's most conservative members, said the plan did not go far enough in scaling back the federal government's role, highlighting Republicans' struggle to craft legislation to revamp a sector that accounts for one-sixth of the world's largest economy.

Mr Paul said fundamental problems still remain that would leave taxpayers subsidising health insurance companies. “I want the bill to look more like a repeal bill,” Mr Paul told MSNBC on Friday.

While Republicans control both chambers of Congress and the White House, the party's efforts to unwind Obamacare has been dogged by internal conflicts between moderate and hard-line members of the party.

Trump publicly celebrated the House bill's passage, only to criticise it in private as “mean.” This week he called for a health plan “with heart.”

Responding to the Senate draft, Mr Obama posted on Facebook: “If there's a chance you might get sick, get old, or start a family“ this bill will do you harm.”

The Senate bill's real-world financial impact is not yet known, but the nonpartisan Congressional Budget Office is expected to provide an estimate early next week.